#like half of my contributions have just been identifying the knowledge gaps between people as they're talking and
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It's exhausting to be the Expert Advisor on a project to a person thoroughly unfamiliar with the field while simultaneously being the only person who understands how to speak the technical language of said newbie AND the two people supervising the whole mess
#like half of my contributions have just been identifying the knowledge gaps between people as they're talking and#getting them on the same fuckin page#like YES this is a valuable skill but CHRIST it gets tiring#esp when the newbie panicks at the slightest ''I don't know what they want me to do???''#when said supervisor doesn't really understand what they're asking for either. (but the newbie doesn't realize that)#AUGH#quality text post
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Hi,love your writing and was wondering if I could request a John Murphy fluff/angst based on season 2or3 where the reader and him get in an argument about him ‘being with Emori’ but he likes the reader?
John Murphy x Reader: Promises
*Absolutely! Thank you for the suggestion. Also, let's just act like I haven't been MIA for literal months :)
GIF//
Warnings: None to my knowledge!
Word Count: 2078
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“Don’t go,” you begged, grabbing Murphy’s hand as it swung carelessly behind him. When your fingers touched his skin, Murphy stopped immediately. He inhaled heavily through his nose, trying to control the sadness and desire that you sent rippling through his body.
“Murphy, please,” you whimpered.
Murphy’s shoulder dropped as he let the single strap of his backpack slide down his arm. Your eyes lit up, hoping that was a positive sign. Hoping that you were enough to make him stay.
“I can’t.”
“You can,” you said assertively. “Why are you doing this to yourself?”
“You wouldn’t understand,” he replied, apologetic eyes looking at you between half-closed eyelids. He was right. You didn’t understand. He had nothing to apologize for. He didn’t have to prove himself to you. Or ask for your forgiveness. None of the things that his blue eyes seemed to convey.
“You don’t need redemption.”
“But if I go now, maybe when I come back-”
“What?” you interrupted. “Everything will suddenly be different?”
“Is it so wrong to want that?” he questioned softly, a shaky sigh leaving his body. You tightened your grip, white knuckles against red calloused ones. Just another casualty of his bad temper.
“Of course not. But you’re not going to fix anything by leaving. You need to stay. Stay and show them who you can be. Don’t leave and prove them right.”
Murphy dropped his head, fixated on your two hands intertwined. There was a lot more going on than the surface discussion. You danced around being in love by using double meanings and knowing glances. This wasn’t about him leaving to find himself. It was about him leaving you.
Glassy eyes meet together in a flurry of uncertainty and passion. The pit of your stomach churned as Murphy leaned forward and placed a gentle kiss on your lips. They barely touched before he pulled away, eyes closed. It was a kiss that you never wanted to experience, especially being your first.
You knew he was leaving.
“Don’t cry,” he told you, hearing a sniffle escape. His eyes still rested, he quietly spoke, “I will be back. I promise. I have something to come back to.”
“Murphy, I-”
“I promise.” He now faced the reality of the situation, confronting his fears head on as he stared into your bloodshot eyes. There was no way he would ever be the cause of this again. He just needed one chance to make you proud. To clear his name.
“I promise.”
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The taste of dirt and sweat caused you to gag as you were manhandled into the unknown. You had no idea why you were the target of a kidnapping. If anything, you laid low and kept to yourself. Regardless, you followed the directions given to you, fearing what would become of your life if you didn’t.
“I’ve brought you some company!” the voice behind you bellowed. You jumped at the sudden noise, interested in the way he practically sang the announcement.
“Who?” another voice asked, seeming alert and slightly panicked. You knew this voice anywhere and it quickly became clear why you were here. Even still, you obeyed the commands given. If you spoke a word, made any noise, it would be the end of your life.
“Worried, are we?” The man started to laugh heartily as you continued to walk. Every thundering step matched the beating of your heart. What would happen when you finally stopped?
There was no response, so the man began to speak. “Someone who wouldn’t shut up about you. Scared for you. Desperate to see you.”
As if being captured weren’t enough, this was just plain humiliating. He didn’t have to recount all the times you pined after Murphy while he was gone. You lost track of the months it had been since you last saw him. This was not how you wanted to reunite.
“Who. Is. It?” Murphy asked yet again. It was dark and menacing. A resemblance of a person that he used to be. You knew that would always be a part of him. Especially when it involved people that he cared about.
“A girlfriend?” the man guessed. You cringed hearing that word, tormenting and taunting you of what never was. But how Murphy replied was even more heartbreaking.
“Emori?” The man began to cackle once more as Murphy cursed and threatened his life. It was terrible to hear the intensity of his love. How much he cared for someone else while you turned others down, waiting for him.
The man gave you one last shove, causing you to fall to your knees. Through minute gaps in the woven sack over your head, you finally caught an amber hue of light. You groaned in pain, trying your best to stay upright with your hands tied behind your back.
There was a brief moment of silence before another outburst broke out. This time, you heard the scuffling of feet against the floor. Fabric harshly rubbed against a scratchy surface. It sounded like an attempt to escape.
“Let her go!” Murphy yelled.
“Why would I do that? I have everything I need, now. Except for the information.”
“Just let her go and I’ll tell you, okay? I’ll tell you everything,” Murphy frantically said.
“But I’m having so much fun. Maybe just one...little…” A cold blade touched your neck, causing a shriek to escape your throat. He put an ounce of pressure against your rapidly thumping artery.
“I swear to God if you hurt her I will kill you!” Murphy’s voice was full of anguish as it broke here and there. It was a frequency in which you had never heard from him. It was harrowing to witness.
The knife was removed from your neck. In a series of exchanges, Murphy gave him the answer to every single question he asked. When the interrogation was over, you were picked up and moved to a new area. Here, you were tied once more around my stomach.
Then, without warning, the bag was removed from your head. You could barely take in my surroundings before Murphy called your name. Tears fell from your eyes as you saw, for the first time in months, John Murphy. Though you had to admit, he looked worse for wear.
“Murphy,” you cried back, wanting more than anything to be able to touch him. To hug him. To take in his scent. You had been without this man for way too long.
“That’s sweet,” the man, who you could now identify as Titus, interrupted. “But I’ve got what I wanted. For now.” And with that, he turned on his heel and exited the room, leaving you and Murphy alone.
“Oh my God, are you okay?” Murphy asked immediately.
“I’m fine,” you replied. “But you don’t look good at all.”
“Yeah, well, being tortured does that to a person.”
“He tortured you?” you questioned, breath leaving your body. Picturing someone hurting Murphy made you sick.
“A few times,” he shrugged.
You wanted to be happy. You wanted to ask him about his trip. You wanted to know if he discovered himself. If he found who he truly was. But you couldn’t get past the fact that he said another girl’s name.
You never claimed to be anything more than friends, but you thought it went without saying. A person doesn’t just kiss someone before they leave. Or promise that they would come back to you.
“I hate that I have to see you like this,” Murphy finally said, breaking the silence. “I always imagined coming back to camp with Jaha’s group. We just saved the human race, or something like that. But it didn’t matter, because I was looking for you.”
“Not Emori?” you mumbled, mustering up the courage to be so bold. Murphy’s eyes grew wide as he avoided your haunting gaze.
“Look, it wasn’t supposed to- she just- we were,” he tried to explain, slumping over in the process.
“I waited for you. Every day,” you admitted. “The last thing I did before I went to bed was look out the gate for you. Every morning I woke up with the hope that it would be the day you came back to me.”
You started to sob, recounting the loneliness that you felt. And the fear of not knowing Murphy’s fate. Were you holding out for someone who was dead? Was it hopeless to wish that he would keep his promise?
“I turned people down. I kept faith in you. I told everyone how proud I was. And then to know that you weren’t keeping me with you at all. I wasn’t even a passing thought.”
“It’s not like that,” Murphy said.
“But it is. She’s your girlfriend.”
“I don’t- love her,” he said softly, swallowing hard enough to make his entire throat bob up and down.
“Then what?” You were at the tipping point with Murphy. Exasperated with his short answers and frustrated with the secrets he was holding. If he wouldn’t be honest with you now, there was no way you would ever be with him in the future.
“I’ve been through a lot. More than I expected.” He stared into the distance, seemingly void of emotion. It was like he was lost, trying hard to remember something that he pushed away. “I was trapped. By myself. 86 days. You know how I spent that time?”
You shook your head in response. He was still burning holes in the wall, but somehow knew that you replied. He smirked slightly before saying, “I thought about you. And how good it would feel to see you once I was out. Granted, I went absolutely crazy in there, but you kept me as sane as I could be.”
You couldn’t help but to chuckle at this. “I can’t imagine you any more psychotic than you are now.”
“Is that so?” he bantered, catching you out of the corner of his eye.
“You’re a freak,” you teased.
“Why? Because I’ve killed a few people?”
“Yeah, that probably contributes.” The two of you shared a smile, falling back into old patterns. You missed having a person that you could shamelessly be yourself around. The quick wit and sly comments were always absorbed and thrown back by Murphy. No one else stood a chance against you.
“When he said he had someone,” Murphy carried on, “you’re the first person I thought of. But it seemed impossible until I saw you. I don’t know what came over me. I- I was blind with rage. I tried to fight my way out. Because if he hurt you-”
Murphy couldn’t bear to finish the sentence. You didn’t need him to. You knew what was left to say. You heard the distinct difference, the silence that fell, when he realized you were the captured person and not Emori.
“I know that doesn’t make any of this right, but I just wanted that feeling of safety that you gave me. And Emori was there. I misplaced it. And I’m sorry,” Murphy apologized.
“What about Emori, then?” you pressed.
“She’s a good person, and she will understand. I just couldn’t live with myself if I left you again.”
“You mean that?” Murphy simply nodded, outstretching his fingers in your direction. Even though you couldn’t hold hands, the sentiment remained as you reflected his actions. You were two people trying to make your own light in the darkest of situations.
“I love you,” you managed to choke out, taking in the dried blood on his hairline and the bruises on his skin. His pant leg was ripped at the cuff and his hands were caked in dirt. You needed him to know that no matter what happened, now and forever, that he could carry this with him. Even after death, if fate so decided.
“I love you, too,” he said, without hesitation or a second thought. It was something he wished he had told you the night he decided to leave. The only thing he regretted once he left the compound.
But he had the chance to fix all of that. And in that moment, he swore that once you escaped, he would always be there to protect you. He would always console you and your wondering thoughts. He would love you the way that he should have a long time ago.
He promised he would always find a way to come back to you.
He promised he would never leave.
He promised.
**Hey, it's Lainey. Slightly embarrassing but I am back from the grave! I hope you all enjoy this and still love Murphy as much as I do <3
#john murphy#john murphy fanfic#john murphy imagine#john murphy x reader#the100#The 100#the100fanfic#the100fanfiction#the100fic#johnmurphyfic#love#writing#john murphy fanfiction#johnmurphyimagine
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What Neuroscientists Are Discovering About Stuttering
https://sciencespies.com/nature/what-neuroscientists-are-discovering-about-stuttering/
What Neuroscientists Are Discovering About Stuttering
Gerald Maguire has stuttered since childhood, but you might not guess it from talking to him. For the past 25 years, Maguire — a psychiatrist at the University of California, Riverside — has been treating his disorder with antipsychotic medications not officially approved for the condition. Only with careful attention might you discern his occasional stumble on multisyllabic words like “statistically” and “pharmaceutical.”
Maguire has plenty of company: More than 70 million people worldwide, including about 3 million Americans, stutter — that is, they have difficulty with the starting and timing of speech, resulting in halting and repetition. That number includes approximately 5 percent of children, many of whom outgrow the condition, and 1 percent of adults. Their numbers include presidential candidate Joe Biden, deep-voiced actor James Earl Jones and actress Emily Blunt. Though those people and many others, including Maguire, have achieved career success, stuttering can contribute to social anxiety and draw ridicule or discrimination by others.
Maguire has been treating people who stutter, and researching potential treatments, for decades. He receives daily emails from people who want to try medications, join his trials, or even donate their brains to his university when they die. He’s now embarking on a clinical trial of a new medication, called ecopipam, that streamlined speech and improved quality of life in a small pilot study in 2019.
Many famous people have a stutter or did so as a child, including (left to right) presidential candidate Joe Biden, actor James Earl Jones and actor Emily Blunt.
(Left to Right: Michael Stokes; U.S. Embassy photo by S.J. Mayhew; Gage Skidmore)
Others, meanwhile, are delving into the root causes of stuttering, which also may point to novel treatments. In past decades, therapists mistakenly attributed stuttering to defects of the tongue and voice box, to anxiety, trauma or even poor parenting — and some still do. Yet others have long suspected that neurological problems might underlie stuttering, says J. Scott Yaruss, a speech-language pathologist at Michigan State University in East Lansing. The first data to back up that hunch came in 1991, Yaruss says, when researchers reported altered blood flow in the brains of people who stuttered. Over the past two decades, continuing research has made it more apparent that stuttering is all in the brain.
“We are in the middle of an absolute explosion of knowledge being developed about stuttering,” Yaruss says.
There’s still a lot to figure out, though. Neuroscientists have observed subtle differences in the brains of people who stutter, but they can’t be certain if those differences are the cause or a result of the stutter. Geneticists are identifying variations in certain genes that predispose a person to stutter, but the genes themselves are puzzling: Only recently have their links to brain anatomy become apparent.
Maguire, meanwhile, is pursuing treatments based on dopamine, a chemical messenger in the brain that helps to regulate emotions and movement (precise muscle movements, of course, are needed for intelligible speech). Scientists are just beginning to braid these disparate threads together, even as they forge ahead with early testing for treatments based on their discoveries.
Slowed circuitry
Looking at a standard brain scan of someone who stutters, a radiologist won’t notice anything amiss. It’s only when experts look closely, with specialized technology that shows the brain’s in-depth structure and activity during speech, that subtle differences between groups who do and don’t stutter become apparent.
The problem isn’t confined to one part of the brain. Rather, it’s all about connections between different parts, says speech-language pathologist and neuroscientist Soo-Eun Chang of the University of Michigan in Ann Arbor. For example, in the brain’s left hemisphere, people who stutter often appear to have slightly weaker connections between the areas responsible for hearing and for the movements that generate speech. Chang has also observed structural differences in the corpus callosum, the big bundle of nerve fibers that links the left and right hemispheres of the brain.
These findings hint that stuttering might result from slight delays in communication between parts of the brain. Speech, Chang suggests, would be particularly susceptible to such delays because it must be coordinated at lightning speed.
Chang has been trying to understand why about 80 percent of kids who stutter grow up to have normal speech patterns, while the other 20 percent continue to stutter into adulthood. Stuttering typically begins when children first start stringing words together into simple sentences, around age 2. Chang studies children for up to four years, starting as early as possible, looking for changing patterns in brain scans.
It’s no easy feat to convince such young children to hold still in a giant, thumping, brain-imaging machine. The team has embellished the scanner with decorations that hide all the scary parts. (“It looks like an ocean adventure,” Chang says.) In kids who lose their stutter, Chang’s team has observed that the connections between areas involved in hearing and ones involved in speech movements get stronger over time. But that doesn’t happen in children who continue to stutter.
In another study, Chang’s group looked at how the different parts of the brain work simultaneously, or don’t, using blood flow as a proxy for activity. They found a link between stuttering and a brain circuit called the default mode network, which has roles in ruminating over one’s past or future activities, as well as daydreaming. In children who stutter, the default mode network seems to insert itself — like a third person butting in on a romantic date — into the conversation between networks responsible for focusing attention and creating movements. That could also slow speech production, she says.
These changes to brain development or structure might be rooted in a person’s genes, but an understanding of this part of the problem has also taken time to mature.
All in the family
In early 2001, geneticist Dennis Drayna received a surprising email: “I am from Cameroon, West Africa. My father was a chief. He had three wives and I have 21 full and half siblings. Almost all of us stutter,” Drayna recalls it saying. “Do you suppose there could be something genetic in my family?”
Drayna, who worked at the National Institute on Deafness and Other Communication Disorders, already had a longstanding interest in the inheritance of stuttering. His uncle and elder brother stuttered, and his twin sons did so as children. But he was reluctant to make a transatlantic journey based on an email, and wary that his clinical skills weren’t up to analyzing the family’s symptoms. He mentioned the email to current National Institutes of Health director Francis Collins (director of the National Human Genome Research Institute at that time), who encouraged him to check it out, so he booked a ticket to Africa. He has also traveled to Pakistan, where intermarriage of cousins can reveal gene variants linked to genetic disorders in their children.
Even with those families, finding the genes was slow going: Stuttering isn’t inherited in simple patterns like blood types or freckles are. But eventually, Drayna’s team identified mutations in four genes — GNPTAB, GNPTG and NAGPA from the Pakistan studies, and AP4E1 from the clan in Cameroon — that he estimates may underlie as many as one in five cases of stuttering.
Oddly, none of the genes that Drayna identified have an obvious connection to speech. Rather, they all are involved in sending cellular materials to the waste-recycling compartment called the lysosome. It took more work before Drayna’s team linked the genes to brain activity.
They started by engineering mice to have one of the mutations they’d observed in people, in the mouse version of GNPTAB, to see if it affected the mice’s vocalizations . Mice can be quite chatty, but much of their conversation takes place in an ultrasonic range that people can’t hear. Recording the ultrasonic calls of pups, the team observed patterns similar to human stuttering. “They have all these gaps and pauses in their train of vocalizations,” says Drayna, who cowrote an overview of genetics research on speech and language disorders for the Annual Review of Genomics and Human Genetics.
Still, the team struggled to spot any clear defect in the animals’ brains — until one determined researcher found that there were fewer of the cells called astrocytes in the corpus callosum. Astrocytes do big jobs that are essential for nerve activity: providing the nerves with fuel, for example, and collecting wastes. Perhaps, Drayna muses, the limited astrocyte population slows down communication between the brain hemispheres by a tiny bit, only noticeable in speech.
Researchers created mice with a mutation in a gene that, in people, is linked to stuttering. The mutant mice vocalized haltingly, with longer pauses between syllables, similar to what’s seen in human stuttering.
(Adapted from T.D. Barnes et al./Current Biology 2016; T.Han et al./PNAS 2019; Knowable Magazine)
Drayna’s research has received mixed reviews. “It’s really been the pioneering work in the field,” says Angela Morgan, a speech-language pathologist at the University of Melbourne and Murdoch Children’s Research Institute in Australia. On the other hand, Maguire has long doubted that mutations in such important genes, used in nearly all cells, could cause defects only in the corpus callosum, and only in speech. He also finds it difficult to compare mouse squeaks to human speech. “That’s a bit of a stretch,” he says.
Scientists are sure there are more stuttering genes to find. Drayna has retired, but Morgan and collaborators are initiating a large-scale study in the hopes of identifying additional genetic contributors in more than 10,000 people.
The dopamine connection
Maguire has been tackling stuttering from a very different angle: investigating the role of dopamine, a key signaling molecule in the brain. Dopamine can ramp up or down the activity of neurons, depending on the brain location and the nerve receptors it sticks to. There are five different dopamine receptors (named D1, D2, and so on) that pick up the signal and respond.
During the 1990s, Maguire and colleagues were among the first to use a certain kind of brain scan, positron emission tomography, on people who stutter. They found too much dopamine activity in these people’s brains. That extra dopamine seems to stifle the activity of some of the brain regions that Chang and others have linked to stuttering.
Backing up the dopamine connection, other researchers reported in 2009 that people with a certain version of the D2 receptor gene, one that indirectly enhances dopamine activity, are more likely to stutter.
So Maguire wondered: Could blocking dopamine be the answer? Conveniently, antipsychotic drugs do just that. Over the years, Maguire has conducted small, successful clinical studies with these medications including risperidone, olanzapine and lurasidone. (Personally, he prefers the last because it doesn’t cause as much weight gain as the others.) The result: “Your stuttering won’t completely go away, but we can treat it,” he says.
None of those medications are approved for stuttering by the US Food and Drug Administration, and they can cause unpleasant side effects, not just weight gain but also muscle stiffness and impaired movement. In part, that’s because they act on the D2 version of the dopamine receptor. Maguire’s new medication, ecopipam, works on the D1 version, which he expects will diminish some side effects — though he’ll have to watch for others, such as weight loss and depression.
In a small study of 10 volunteers, Maguire, Yaruss and colleagues found that people who took ecopipam stuttered less than they did pre-treatment. Quality-of-life scores, related to feelings such as helplessness or acceptance of their stutter, also improved for some participants.
Ten adult volunteers who stuttered were given ecopipam, a drug that blocks one version of the dopamine receptor, for 8 weeks. They stuttered significantly less when they were on the drug than they had before the treatment.
(G.A. Maguire et al./Annals of Clinical Psychiatry 2019/Knowable Magazine)
Ecopipam isn’t the only treatment under consideration. Back in Michigan, Chang hopes that stimulation of specific parts of the brain during speech could improve fluency. The team uses electrodes on the scalp to gently stimulate a segment of the hearing area, aiming to strengthen connections between that spot and the one that manages speech movements. (This causes a brief tickle sensation before fading, Chang says.) The researchers stimulate the brain while the person undergoes traditional speech therapy, hoping to enhance the therapy’s effects. Because of the Covid-19 pandemic, the team had to stop the study with 24 subjects out of a planned 50. They’re analyzing the data now.
Connecting the dots
Dopamine, cellular waste disposal, neural connectivity — how do they fit together? Chang notes that one of the brain’s circuits involved in stuttering includes two areas that make and use dopamine, which might help explain why dopamine is important in the disorder.
She hopes that neuroimaging can unite the different ideas. As a first stab, she and collaborators compared the problem areas identified by her brain scans to maps of where various genes are active in the brain. Two of Drayna’s genes, GNPTG and NAGPA, were active at high levels in the speech and hearing network in the brains of non-stutterers, she saw. That suggests those genes are really needed in those areas, bolstering Drayna’s hypothesis that defects in the genes would interfere with speech.
The team also observed something novel: Genes involved in energy processing were active in the speech and hearing areas. There’s a big rise in brain activity during the preschool years, when stuttering tends to start, Chang says. Perhaps, she theorizes, those speech-processing regions don’t get all the energy they need at a time when they really need to be cranking at maximum power. With that in mind, she plans to look for mutations in those energy-control genes in children who stutter. “There are obviously a lot of dots that need to be connected,” she says.
Maguire is also connecting dots: He says he’s working on a theory to unite his work with Drayna’s genetic findings. Meanwhile, after struggling through med school interviews and choosing a career in talk therapy despite his difficulties with speech, he’s hopeful about ecopipam: With colleagues, he’s starting a new study that will compare 34 people on ecopipam with 34 on placebo. If that treatment ever becomes part of the standard stuttering tool kit, he will have realized a lifelong dream.
Knowable Magazine is an independent journalistic endeavor from Annual Reviews.
#Nature
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Where does the controversial finding that adult human brains don't grow new neurons leave ongoing research?
by Janice R. Naegele
Could it be that a baby has all the brain cells she ever will? Jv Garcia on Unsplash, CC BY
Scientists have known for about two decades that some neurons – the fundamental cells in the brain that transmit signals – are generated throughout life. But now a controversial new study from the University of California, San Francisco, casts doubt on whether many neurons are added to the human brain after birth.
As a translational neuroscientist, this work immediately piqued my interest. It has direct implications for the research my lab does: We transplant young neurons into damaged brain areas in mice in an attempt to treat epileptic seizures and the damage they’ve caused. Like many labs, part of our work is based on a foundational belief that the hippocampus is a brain region where new neurons are born throughout life.
If the new study is right, and human brains for the most part don’t add new neurons after infancy, researchers like me need to reconsider the validity of the animal models we use to understand various brain conditions – in my case temporal lobe epilepsy. And I suspect other labs that focus on conditions including drug addiction, depression and post-traumatic stress disorder are thinking about what the UCSF study means for their investigations, too.
In the brain of a baby who died soon after birth, there are many new neurons (green in this image) in the hippocampus. Sorrells et al, CC BY-ND
When and where are new neurons born?
No doubt, the adult human brain is able to learn throughout life and to change and adapt – a capability brain scientists call neuroplasticity, the brain’s ability to reorganize itself by rewiring connections. Yet, a central dogma in the field of neuroscience for nearly 100 years had been that a child is born with all the neurons she will ever have because the adult brain cannot regenerate neurons.
Just over half a century ago, researchers devised a way to study proliferation of cells in the mature brain, based on techniques to incorporate a radioactive label into new cells as they divide. This approach led to the startling discovery in the 1960s that rodent brains actually could generate new neurons.
Neurogenesis – the production of new neurons – was previously thought to only occur during embryonic life, a time of extremely rapid brain growth and expansion, and the rodent findings were met with considerable skepticism. Then researchers discovered that new neurons are also born throughout life in the songbird brain, a species scientists use as a model for studying vocal learning. It started to look like neurogenesis plays a key role in learning and neuroplasticity – at least in some brain regions in a few animal species.
Even so, neuroscientists were skeptical that many nerve cells could be renewed in the adult brain; evidence was scant that dividing cells in mammalian brains produced new neurons, as opposed to other cell types. It wasn’t until researchers extracted neural stem cells from adult mouse brains and grew them in cell culture that scientists showed these precursor cells could divide and differentiate into new neurons. Now it is generally well accepted that neurogenesis takes place in two areas of the adult rodent brain: the olfactory bulbs, which process smell information, and the hippocampus, a region characterized by neuroplasticity that is required for forming new declarative memories.
Adult neural stem cells cluster together in what scientists call niches – hotbeds for cultivating the birth and growth of new neurons, recognizable by their distinctive architecture. Despite the mounting evidence for regional growth of new neurons, these studies underscored the point that the adult brain harbors only a few stem cell niches and their capacity to produce neurons is limited to just a few types of cells.
With this knowledge, and new tools for labeling proliferating cells and identifying maturing neurons, scientists began to look for postnatal neurogenesis in primate and human brains.
A mouse neural stem cell (blue and green) grows in a lab dish. Can human brain cells do what rodent brain cells do? Mark McClendon, Zaida Alvarez Pinto, Samuel I. Stupp, Northwestern University, Evanston, IL, CC BY-NC
What’s happening in adult human brains?
Many neuroscientists believe that by understanding the process of adult neurogenesis we’ll gain insights into the causes of some human neurological disorders. Then the next logical step would be trying to develop new treatments harnessing neurogenesis for conditions such as Alzheimer’s disease or trauma-induced epilepsy. And stimulating resident stem cells in the brain to generate new neurons is an exciting prospect for treating neurodegenerative diseases.
Because neurogenesis and learning in rodents increases with voluntary exercise and decreases with age and early life stress, some workers in the field became convinced that older people might be able to enhance their memory as they age by maintaining a program of regular aerobic exercise.
However, obtaining rigorous proof for adult neurogenesis in the human and primate brain has been technically challenging – both due to the limited experimental approaches and the larger sizes of the brains, compared to reptiles, songbirds and rodents.
Researchers injected a compound found in DNA, nicknamed BrdU to identify brand new neurons in human adult hippocampus – but the labeled cells were extremely rare. Other groups demonstrated that adult human brain tissue obtained during neurosurgery contained stem cell niches that housed progenitor cells that could generate new neurons in the lab, showing that these cells had an inborn neurogenic capacity, even in adults.
But even when scientists saw evidence for new neurons in the brain, they tended to be scarce. Some neurogenesis experts were skeptical that evidence based on incorporating BrdU into DNA was a reliable method for proving that new cells were actually being born through cell division, rather than just serving as a marker for other normal cell functions.
Further questions about how long human brains retain the capacity for neurogenesis arose in 2011, with a study that compared numbers of newborn neurons migrating in the olfactory bulbs of infants versus older individuals up to 84 years of age. Strikingly, in the first six months of life, the baby brains contained lots of chains of young neurons migrating into the frontal lobes, regions that guide executive function, long-range planning and social interactions. These areas of the human cortex are hugely increased in size and complexity compared to rodents and other species. But between 6 to 18 months of age, the migrating chains dwindled to a thin stream. Then, a very different pattern emerged: Where the migrating chains of neurons had been in the infant brain, a cell-free gap appeared, suggesting that neural stem cells become depleted during the first six months of life.
Questions still lingered about the human hippocampus and adult neurogenesis as a source for its neuroplasticity. One group came up with a clever approach based on radiocarbon dating. They measured how much atmospheric ¹⁴C – a radioactive isotope derived from nuclear bomb tests – was incorporated into people’s DNA. This method suggested that as many as 700 new cells are added to the adult human hippocampus every day. But these findings were contradicted by a 2016 study that found that the neurogenic cells in the adult hippocampus could only produce non-neuronal brain cells called microglia.
Rethinking neurogenesis research
Now the largest and most comprehensive study conducted to date presents even stronger evidence that robust neurogenesis doesn’t continue throughout adulthood in the human hippocampus – or if it does persist, it is extremely rare. This work is controversial and not universally accepted. Critics have been quick to cast doubt on the results, but the finding isn’t totally out of the blue.
So where does this leave the field of neuroscience? If the UCSF scientists are correct, what does that mean for ongoing research in labs around the world?
It’s much easier to work with rodent brains than human ones. This is a stained image of the hippocampus and neurons of a mouse with neurodegenerative disease. NICHD/I. Williams, CC BY
Because lots of studies of neurological diseases are done in mice and rats, many scientists are invested in the possibility that adult neurogenesis persists in the human brain, just as it does in rodents. If it doesn’t, how valid is it to think that the mechanisms of learning and neuroplasticity in our model animals are comparable to those in the human brain? How relevant are our models of neurological disorders for understanding how changes in the hippocampus contribute to disorders such as the type of epilepsy I study?
In my lab, we transplant embryonic mouse or human neurons into the adult hippocampus in mice, after damage caused by epileptic seizures. We aim to repair this damage and suppress seizures by seeding the mouse hippocampus with neural stem cells that will mature and form new connections. In temporal lobe epilepsy, studies in adult rodents suggest that naturally occurring hippocampal neurogenesis is problematic. It seems that the newborn hippocampal neurons become highly excitable and contribute to seizures. We’re trying to inhibit these newborn hyperexcitable neurons with the transplants. But if humans don’t generate new hippocampal neurons, then maybe we’re developing a treatment in mice for a problem that has a different mechanism in people.
Perhaps our species has evolved separate mechanisms for neuroplasticity, distinct from those used by species such as rats and mice. One possibility is that there are other sites in the human brain where neurogenesis occurs - its a big structure and more exploration will be necessary. If it turns out to be true that the human brain has a diminished capacity for neurogenesis after birth, the finding will have important implications for how neuroscientists like me think about tackling brain disorders.
Perhaps most importantly, this work underscores how crucial it is to learn how to increase the longevity of the neurons we do have, born early in life, and how we might replace or repair neurons that become damaged.
Janice R. Naegele is an Alan M Dachs Professor of Science and Professor of Biology, Neuroscience and Behavior at Wesleyan University
This article was originally published on The Conversation.
#science#neuroscience#memory#learning#stem cells#brain#the human brain#epilepsy#neurogenesis#neuroplasticity#neurons#brain disorder#brain cells#neuron
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Wednesday Roundup 29.11.18
Another week another grab bag of comics in what might be one of the highest rated weeks of the Roundup since I started over a year ago! But how does everyone hold up? How do they all compare? I’m asking for dramatizing’s sake but genuinely there’s nothing in this week that isn’t immensely enjoyable if they even remotely pique your interests. GREAT week for comics, everyone. GG.
Tesladyne’s Atomic Robo, Image’s Black Magick, DC’s Super Sons, IDW’s Teenage Mutant Ninja Turtles/Ghostbusters II, IDW’s Transformers: Lost Light
Tesladyne’s Atomic Robo and the Spectre of Tomorrow #2 Brian Clevinger, Scott Wegener, Anthony Clark, Jeff Powell
There is a certain amount of dry wit and scientific community knowledge that is instrumental to getting the full experience out of the clever writing and deceptively simplistic design of Atomic Robo, and for the past few months I’ve been making a solid attempt to evaluate these comics and Robo himself based on the entertainment received without much of that. And, in all honesty, the more I’ve looked into this the more I wonder if that’s the wrong approach for “unbiased” evaluation to begin with.
For example, I’ve been very firm on my description of Usagi Yojimbo as being one of those great comics that only gets more and more enriching as you grow a personal interest in history, Japanese culture, and mythologizing -- it’s far enough removed from our actual realities and accessible enough that I recommend it to people who don’t have those interests, but I find that those interests add so much more to the experience. The simple designs, the consistency, the way the narrative is built in episodic spurts more than long form narrative -- those are all reasons I can in good faith recommend these comics to people outside of niche interests, but those niche interests add so much to any reading that it’s difficult to really express why anyone would want to read without so much as acknowledging it.
That all said, this particular issue continues that same level of quality and intrigue, but also rewards the emotional investment you may have in the characters involved. PersonallyI relate a lot more to Robo’s sense of self-exile and reclusive depression which only causes more and more problems to pile up far more than I’d have ever thought I would, and I don’t think I’d be alone in that. There’s also the long time readers’ reward in seeing consequences to that stollen crystal from Doctor Dinosaur’s island ages ago. All great stuff which is only more greatly emphasized by the creative use of familiar real world scientific organizations and entities wrapped up in this bizarre and surreal reality of Atomic Robo.
Image’s Black Magick (2015-present) #9 Greg Rucka, Nicola Scott
Sometimes the real value of storytelling lies less in identifying the complete package and more in being able to identify the way it weaves multiple elements and even genres at once to provide a new kind of satisfying narrative. And it’s in that way that I think Black Magick has so quickly become not only one of my favorite Greg Rucka and Nicola Scott comics, but one of my favorite recent publications in general.
Black Magick follows a noir-style crime drama in structure, but its embrace of the supernatural and, especially, in witching stories provide the sort of edge that makes the tiredness of the former genre feel fresh even in the heavily saturated market for procedurals we have currently, while the latter feels completely reborn from that small but influential boom we felt in the 90s. I have never been closer to re-marathoning The Craft, Practical Magic and Charmed outside of the Halloween season. But each new issue of Black Magick brings me that step closer.
This issue also happens to follow the very specific to this week trend of leaning heavily on emotional stakes to really pull itself and its characters above even the thickest of genre settings however, and Black Magick specifically manages that while maintaining an incredibly tight hold on Rowan’s perspective. Which is fascinating because on reread you really realize how much the POV shifts away from Rowan and onto the other characters and their subplots but in reflection it all feels like it’s only in service to Rowan’s main story more than anything else.
Nicola Scott continues to prove she is perhaps the most gifted and, really, the most prolific of comic book artists in the modern era and I maintain that seeing the true extent of her talents is best assessed by reading this comic and just allowing yourself to be blown away by it all.
This issue also gets major props for introducing a familiar. Good, comic. Perhaps not as action filled or breathtaking as the last issue which was a nail biter from start to finish, but most certainly deserving of those 4/5 stars.
DC’s Super Sons (2017-present) Annual #1 Peter J. Tomasi, Paul Pelletier, Cam Smith, HI-FI
If you’re one of those people -- and let me absolutely clear that it is more than understandable to be one of these people -- who find super pets and the absolute general ridiculousness of a storyline that involves super animals in any capacity with a timeline that makes no sense and the only real dialogue that matters being literal growls barks and yips, this is not an issue worth your $4.99, you’ll hate it and be annoyed with people like me screaming from the rooftops that you should buy it and read it and love it. And that is completely and utterly fine and reasonable.
I am not fine or reasonable, however, and this is literally the most rewarding $4.99 I’ve spent on a comic in ages. Because no joke there were several times while I was liveblogging this issue both on my main blog and to my friends in PMs that I was literally in tears crying with laughter because
because
Holy shit guys.
In recent years a continued criticism I have carried for superhero comics is that there is a huge tone problem, in that there is a genre’s worth of tones and atmospheres that could be played off of to give at least each individual book if not each individual issue its own feeling and its own intrigue that would set it apart from the rest of the line that given week. DC, especially, has contributed greatly to this tone problem because as I’ve said many times, there was about five years there where even the color palettes for their comics had no variation between them. And it was maddening.
So to have something goofy, to have something different, and to have it be fun, enjoyable, full of twists and turns, and not so damn determined to take itself beyond seriously, it makes this comic throwback feel like a breath of fresh air in the most necessary of ways.
And I should be clear, I don’t mean that this comic is for everyone, or that Super Sons as a comic in general doesn’t manage to strike that cord a lot since it really is one of the most enjoyable comics DC has put out in years, but this really felt like a treat, an additional, ridiculous, hilarious story set so far apart from what’s come before. It’s greatly enjoyable. Genuinely deserve of my coveted 5/5 stars.
IDW’s Teenage Mutant Ninja Turtles/Ghostbusters II (2017) #5 (of 5) Erik Burnham, Tom Waltz, Dan Shoening, Charles Paul Wilson III, Luis Antonio Delgado
We finally come to an end of this second giant mashup of Ghostbusters and Teenage Mutant Ninja Turtles, truly the sort of framework and pairing that is as old as time, and I get to reward everyone’s patience with me reviewing these for a month an a half straight with some final thoughts of sorts.
I compliment both of these writers quite a bit for their respective contributions and the absolute mastery they both have shown for the voices of their respective franchises, but as this week is pretty well summed up with Rena Waxes Philosophically And Is Old, I think both of our times are better spent here by pointing out something a bit different that really came together with this issue. And that’s that for how pitch perfect these writers are for capturing the long expected voices of these beloved characters, the real remarkable compliment I can give them is how they have uniquely captured and redefined these voices to really make them their own.
Despite how much my childhood might have desired these team ups (and believe me, it so did) the fact is that these interactions and these relationships are utterly a modern invention, and what could easily fail outside of the concept states instead flourishes with us here specifically because they are sticking to their guns and not always angling for the obvious route with these interactions. That’s what makes all of this so fascinating and so rewarding as a fan.
In comparison to the predecessor, Teenage Mutant Ninja Turtles/Ghostbusters II does not have as tight of a storyline with a steady but consistent pacing and understanding of where it’s going. But I think because that set up was taking care of in the original these five issues allowed for more experimentation and more concentration on character development and fun scenarios. So if you’re far more invested in character interactions and in comics taking full advantage of the outrageous and unique tone of its medium, there’s probably all the more for you to enjoy with this compared to the first. But at the same time, it would be lying to say that the main driving plot and stakes, with Darius Dun’s ghost and the Fast Forward Evil Turtles-lite trying to harvest souls in a complicated and underused concept didn’t come off as overall a bit weaker than the original.
All that said, ultimately this comic is a joy for fans and it seems to be aimed quite specifically at that audience either way. And in that case I have to give it my highest regards.
IDW’s Transformers: Lost Light (2016-present) #11 James Roberts, Jack Lawrence, Joana Lafuente
Ever since the last arc of James Robert’s parent series, More Than Meets the eye, there’s been a few gaps in the concept of what happened on the Lost Light during and after the mutiny, whether or not the crew saw the Rod Squad’s las message, and especially curious to people like me who can’t help themselves but love our affable and entirely flawed co-Captain Rodimus, what was his final request for his burial and what not since we saw the rest of the crew’s.
And in the second part of this “Mutineer Trilogy” that we have for Lost Light, we are at long last getting our answers to many of those questions. And for a reveal that was a year coming, the Lost Light manages to pack all the twists, turns, and punches that we could hope to expect!
It’s fascinating to see Getaway’s sense of grandeur when it comes to himself, his plans, and really the whole driving force with the mutiny, but I really find that where Roberts’ writing and where we as readers get the most out of is the interesting and very layered sense that Roberts has for the lore of the Transformers. It feels like every subtle piece of dialogue, whether it concerns lore and mythology of the universe or not, is really weaved throughout with a submersion in this fictional culture. And that, especially, is really revealing here. It’s a very rewarding way to handle lore and I greatly appreciate it.
One that does make me apprehensive with the turns Lost Light has taken most recently, however, is that moral grayness sometimes feels really blurred with a light take or even somewhat forgiving light given to what are undeniably and outright stated as fascist and genocidal elements of the Transformers’ past, especially Megatron. Having this issue completely dedicated to Getaway’s perspective while tackling these themes doesn’t really help because he is most egregiously one of the most villainous and traitorous characters the series has tackled, but while it feels like he’s only using the aghast feelings of the crew toward Megatron, ultimately he’s the only one who gives a speech against Megatron’s past of genocide and fascism while also taking over in the most truly reprehensible and fascist ways possible himself. This is further blurred by having some very topical buzz words like “fake news” uttered by Getaway in a... lbr pretty nonsensical way in-universe, but then have him going around imprisoning or hideously killing all of the crew which doesn’t agree with him.
I’m basically waiting for Roberts to fully address all of this in the story but right now it feels very much like “both sides are extreme and bad” mentality that, given Roberts’ politics and statements irl, I don’t think is what he ultimately wants this story to be coming away as, but I’m nervous and would like for things to tread lightly considering the current environment.
ALL of my apprehensions and concerns out of the way, this is still a fascinating and ultimately fantastic comic that I really truly enjoy and would love to see more of because if Roberts’ Transformers is guilty of anything it’s definitely guilty of raising my expectations and setting that bar so high because of how good and how complicated and interesting all of it ca be in the right hands.
Hey there! We finish up another pretty fun, if not quick, week in comics with lots of stories and characters, and another pretty great time from yours truly. And if you enjoy these write-ups or anything else I do whether it be the Roundups, my Rambles, my personal creative projects, or you’re interested in my upcoming podcast, you can help contribute through donations to my Ko-Fi, Patreon, or PayPal. For as little as $1 per project, you make all of this possible.
You could also support me by going to my main blog, @renaroo, where I’ll soon be listing prices and more for art and writing commissions.
RenaRoo Ko-Fi | RenaRoo Patreon | RenaRoo PayPal
#Rena Roundups#Wednesday Spoilers#SPOILERS#Atomic Robo and the Spectre of Tomorrow#Black Magick#Super Sons (2017 )#Teenage Mutant Ninja Turtles/Ghostbusters II#Transformers: Lost Light (2016 )
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How to Double Your Trading Returns with Minimal Risk
This post originally appeared on Wealth Within.
By Janine Cox | Published 12 November 2019
I remember presenting to an audience around ten years ago and following my presentation a gentleman came up to me as he wanted to show how he had doubled his money. He then reached into his pocket and pulled out a $50 note, folded it in half and said “there you go!” While he had a desire to make money in the stock market, he was skeptical although he clearly had a great sense of humour.
In all seriousness, while you can double your trading returns in the stock market with minimal risk, I realized that the gentleman’s response above merely reflects the skepticism that is widely held about the possibility of making great returns in the market. And while I understand why people may be skeptical, this is often based on fear and incorrect perceptions rather than founded on solid facts.
The statistics don’t lie
We have a 60 second trading assessment survey on our website that helps individuals identify what they may need if they want to achieve their goals in the stock market. Of those who have completed the survey, around 87.65 per cent said they have limited to no knowledge when it comes to trading the stock market, while 80.80 per cent state they are either not confident or only somewhat confident with their trading but they are still not profitable.
What was even more interesting, however, is that over 88 per cent of all respondents said they wanted to take the bull by the horns to gain a quality education, yet the majority had not done this, and statistics indicate that they never will. As Thomas Edison once said “Opportunity is missed by most people because it is dressed in overalls and looks like work”.
In regards to trading successfully and profitably, the statistics prove time and again that people fail to commit the necessary time and money because it takes sustained effort and involves a level of risk that they may fail. So all jokes aside, this is why those who have the potential to double their money will never give themselves the opportunity to do so because they fail to do what they know they should be doing, although this needn’t be the case.
To put this into perspective, we recently received an email from a client who had enrolled in our Diploma of Share Trading and Investment course in July of this year, and who had attended one of our seminars in Melbourne around 18 years ago. He literally started out with the email by saying “some people just don’t get it, and that’s me”.
You see, he communicated that he had wandered around in the trading wilderness looking at this and that, listening to many people and buying everyone’s program (except ours) in the hope of succeeding. But in all those years he had lost more money than he ever made from the market, as he had not learnt to protect his capital, among other things.
And it wasn’t until he was between a rock and a hard place that he realized he needed to do something about his trading. With his wife’s encouragement, he decided to finally enrol in our Diploma course, and while at the time it appeared to be a lot of money (as he was a pensioner), he had come to the conclusion about how much time he had already wasted, as he realized how much better off he would have been in so many ways had he acted sooner.
He finished up his email by saying that some people are just so thick and “know it all’s”, that they just don’t get it, BUT now I do and I have done something about my future.
Remember, the statistics don’t lie. Over 90 percent of people who believe they are traders fail to make money consistently because they focus their attention in all the wrong places.
The challenge with doubling your trading returns
You see the challenge with reading books, watching YouTube videos or attending weekend workshops is that many people only gain a fraction of the information they require to be consistently profitable in the stock market. But people are attracted to this way of learning because it is cheap and involves very little risk or effort, which is why Edison states that most people miss the opportunity.
In fact, many people end up scratching their head in confusion when they try to apply what they have learnt in a book or at a workshop to the real world of trading. That’s because they either don’t understand how to apply the knowledge they have gained or there are gaps in the information they have received. In the end, it costs them in lost capital and opportunity, which affects the quality of life for them and their family.
In essence, because the opportunity looked like work, they failed to allocate the necessary time and resources needed to be successful, and so achieved the opposite of what they desired.
Unfortunately, too many people believe that an investment in knowledge is a cost rather than an investment. Therefore, they focus on what education is costing them in time and money rather than looking at it from the perspective of how much it is costing them by not having the right knowledge or education.
But when you arm yourself with the correct knowledge and support, you will confidently begin your journey towards securing your financial future, and in doing so, you will come to know that you can deliver consistent results time and again, rather than just hoping you can. Remember, the statistics don’t lie. A lack of education or the wrong education costs you dearly both in time and money, so be careful about the path your take or who you choose to learn from.
Your trading returns are the most important factor when investing
Research conducted for the Australian Stock Exchange (ASX) indicates that Australian investors rate the return on their investments as the most important factor when looking to invest followed by either a guaranteed or stable return. And investors expect these returns to be in the order of 8 to 9 per cent per annum.
So what the research is suggesting is that investors expect high returns with no risks attached, which we all know is pretty unrealistic. But it is this thinking that is holding a lot of investors back from achieving the returns they desire.
The research also demonstrates that most investors prefer to do their own homework when it comes to investing with a considerable number relying on third party broker reports to make their investment decisions. But many are still unhappy with the returns they are achieving, as it is well below the expected 8 to 9 per cent per annum.
That said, many also prefer to make their own decisions despite not having much knowledge or understanding about the stock market, yet they still expect to achieve returns in the vicinity of 8 to 9 per cent. Given these unrealistic expectations, it’s no wonder that 90 per cent of those who invest in the stock market either breakeven or lose money.
So, let me ask, how much are you willing to invest in yourself in order to know how to double your returns?
Would an education be expensive if you could double your returns?
Let’s assume you invest $50,000 and you make an 8 per cent return, you will have made $4,000. Now, what If you made 12.5 per cent per annum, then your return would be $6,250, which equates to an improvement on your previous return of $2,250 or over 56 per cent.
It may surprise you to learn that over a 10 year period, trading the top 20 stocks on the ASX using a simple trend line and a stop loss, Dale Gillham achieved a return of around 12.50 per cent per annum in his latest book Accelerate Your Wealth, so these types of returns are very achievable.
So, what if you could double your returns without dramatically increasing your risk? How would that make you feel and how would that change your life?
Now imagine that you have doubled your returns without dramatically increasing the time you currently put in. No doubt you will begin to see why having a much better understanding about the stock market and how to trade it will change your life.
Let me show why a lack of knowledge is costing you a lot of money.
Let’s assume you have $50,000 to invest and you decide you will also contribute $200 each month in savings to invest in the market. Using ASIC’s compound interest calculator with an interest rate of 10 per cent, over 10 years, you can see your total investment would grow to over $176,000.
Figure 1: 10% return over ten years
Now let’s consider what the outcome would be if you invested the same amount but you achieved a return of 20 per cent. As you can see, your return would grow to over $438,000 or an improvement of around $262,300 over ten years. Now that has to be worth the value of putting on those overalls and getting a solid education.
Figure 2: 20% return over ten years
Unfortunately, it’s a lack of knowledge combined with fear, and our limiting beliefs about the stock market that is costing many individuals far more than they ever realise.
Benjamin Franklin once said “An investment in knowledge pays the best interest” while Jim Rohn said “If someone is going down the wrong road, he doesn't need motivation to speed him up, what he needs is an education to turn him around”.
Einstein was also famously known for saying “Education is the progressive realisation of our ignorance”. In fact, it’s a well-known fact that ignorance is far more expensive than education.
While many of you will appreciate the wisdom of what these gentleman are saying, you will continue to rely on hot tips or interact in chat forums and continue watching YouTube in the hope you will achieve high returns for little to no effort. But we all know that this results in disappointment because it’s not realistic.
So ask yourself, what’s it going to take for you to make the decision to put on those overalls and take on the opportunity to be able to achieve the results you’ve been seeking? As Dale Gillham’s (Chief Analyst at Wealth Within) late mentor used to say: “have a great day and make it a great day”. In other words, put on your overalls and grab those opportunities to ensure you achieve your goals.
Others who read this also enjoyed reading:
Why Backtesting Increases Your Trading Profits
Trading Options: A Reality Check
How to Increase the Odds of Winning Trade
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Where does the controversial finding that adult human brains don't grow new neurons leave ongoing research?
http://bit.ly/2IrPwoA
Could it be that a baby has all the brain cells she ever will? Jv Garcia on Unsplash, CC BY
Scientists have known for about two decades that some neurons – the fundamental cells in the brain that transmit signals – are generated throughout life. But now a controversial new study from the University of California, San Francisco, casts doubt on whether many neurons are added to the human brain after birth.
As a translational neuroscientist, this work immediately piqued my interest. It has direct implications for the research my lab does: We transplant young neurons into damaged brain areas in mice in an attempt to treat epileptic seizures and the damage they’ve caused. Like many labs, part of our work is based on a foundational belief that the hippocampus is a brain region where new neurons are born throughout life.
If the new study is right, and human brains for the most part don’t add new neurons after infancy, researchers like me need to reconsider the validity of the animal models we use to understand various brain conditions – in my case temporal lobe epilepsy. And I suspect other labs that focus on conditions including drug addiction, depression and post-traumatic stress disorder are thinking about what the UCSF study means for their investigations, too.
In the brain of a baby who died soon after birth, there are many new neurons (green in this image) in the hippocampus. Sorrells et al, CC BY-ND
When and where are new neurons born?
No doubt, the adult human brain is able to learn throughout life and to change and adapt – a capability brain scientists call neuroplasticity, the brain’s ability to reorganize itself by rewiring connections. Yet, a central dogma in the field of neuroscience for nearly 100 years had been that a child is born with all the neurons she will ever have because the adult brain cannot regenerate neurons.
Just over half a century ago, researchers devised a way to study proliferation of cells in the mature brain, based on techniques to incorporate a radioactive label into new cells as they divide. This approach led to the startling discovery in the 1960s that rodent brains actually could generate new neurons.
Neurogenesis – the production of new neurons – was previously thought to only occur during embryonic life, a time of extremely rapid brain growth and expansion, and the rodent findings were met with considerable skepticism. Then researchers discovered that new neurons are also born throughout life in the songbird brain, a species scientists use as a model for studying vocal learning. It started to look like neurogenesis plays a key role in learning and neuroplasticity – at least in some brain regions in a few animal species.
Even so, neuroscientists were skeptical that many nerve cells could be renewed in the adult brain; evidence was scant that dividing cells in mammalian brains produced new neurons, as opposed to other cell types. It wasn’t until researchers extracted neural stem cells from adult mouse brains and grew them in cell culture that scientists showed these precursor cells could divide and differentiate into new neurons. Now it is generally well accepted that neurogenesis takes place in two areas of the adult rodent brain: the olfactory bulbs, which process smell information, and the hippocampus, a region characterized by neuroplasticity that is required for forming new declarative memories.
Adult neural stem cells cluster together in what scientists call niches – hotbeds for cultivating the birth and growth of new neurons, recognizable by their distinctive architecture. Despite the mounting evidence for regional growth of new neurons, these studies underscored the point that the adult brain harbors only a few stem cell niches and their capacity to produce neurons is limited to just a few types of cells.
With this knowledge, and new tools for labeling proliferating cells and identifying maturing neurons, scientists began to look for postnatal neurogenesis in primate and human brains.
A mouse neural stem cell (blue and green) grows in a lab dish. Can human brain cells do what rodent brain cells do? Mark McClendon, Zaida Alvarez Pinto, Samuel I. Stupp, Northwestern University, Evanston, IL, CC BY-NC
What’s happening in adult human brains?
Many neuroscientists believe that by understanding the process of adult neurogenesis we’ll gain insights into the causes of some human neurological disorders. Then the next logical step would be trying to develop new treatments harnessing neurogenesis for conditions such as Alzheimer’s disease or trauma-induced epilepsy. And stimulating resident stem cells in the brain to generate new neurons is an exciting prospect for treating neurodegenerative diseases.
Because neurogenesis and learning in rodents increases with voluntary exercise and decreases with age and early life stress, some workers in the field became convinced that older people might be able to enhance their memory as they age by maintaining a program of regular aerobic exercise.
However, obtaining rigorous proof for adult neurogenesis in the human and primate brain has been technically challenging – both due to the limited experimental approaches and the larger sizes of the brains, compared to reptiles, songbirds and rodents.
Researchers injected a compound found in DNA, nicknamed BrdU to identify brand new neurons in human adult hippocampus – but the labeled cells were extremely rare. Other groups demonstrated that adult human brain tissue obtained during neurosurgery contained stem cell niches that housed progenitor cells that could generate new neurons in the lab, showing that these cells had an inborn neurogenic capacity, even in adults.
But even when scientists saw evidence for new neurons in the brain, they tended to be scarce. Some neurogenesis experts were skeptical that evidence based on incorporating BrdU into DNA was a reliable method for proving that new cells were actually being born through cell division, rather than just serving as a marker for other normal cell functions.
Further questions about how long human brains retain the capacity for neurogenesis arose in 2011, with a study that compared numbers of newborn neurons migrating in the olfactory bulbs of infants versus older individuals up to 84 years of age. Strikingly, in the first six months of life, the baby brains contained lots of chains of young neurons migrating into the frontal lobes, regions that guide executive function, long-range planning and social interactions. These areas of the human cortex are hugely increased in size and complexity compared to rodents and other species. But between 6 to 18 months of age, the migrating chains dwindled to a thin stream. Then, a very different pattern emerged: Where the migrating chains of neurons had been in the infant brain, a cell-free gap appeared, suggesting that neural stem cells become depleted during the first six months of life.
Questions still lingered about the human hippocampus and adult neurogenesis as a source for its neuroplasticity. One group came up with a clever approach based on radiocarbon dating. They measured how much atmospheric ¹⁴C – a radioactive isotope derived from nuclear bomb tests – was incorporated into people’s DNA. This method suggested that as many as 700 new cells are added to the adult human hippocampus every day. But these findings were contradicted by a 2016 study that found that the neurogenic cells in the adult hippocampus could only produce non-neuronal brain cells called microglia.
Rethinking neurogenesis research
Now the largest and most comprehensive study conducted to date presents even stronger evidence that robust neurogenesis doesn’t continue throughout adulthood in the human hippocampus – or if it does persist, it is extremely rare. This work is controversial and not universally accepted. Critics have been quick to cast doubt on the results, but the finding isn’t totally out of the blue.
So where does this leave the field of neuroscience? If the UCSF scientists are correct, what does that mean for ongoing research in labs around the world?
It’s much easier to work with rodent brains than human ones. This is a stained image of the hippocampus and neurons of a mouse with neurodegenerative disease. NICHD/I. Williams, CC BY
Because lots of studies of neurological diseases are done in mice and rats, many scientists are invested in the possibility that adult neurogenesis persists in the human brain, just as it does in rodents. If it doesn’t, how valid is it to think that the mechanisms of learning and neuroplasticity in our model animals are comparable to those in the human brain? How relevant are our models of neurological disorders for understanding how changes in the hippocampus contribute to disorders such as the type of epilepsy I study?
In my lab, we transplant embryonic mouse or human neurons into the adult hippocampus in mice, after damage caused by epileptic seizures. We aim to repair this damage and suppress seizures by seeding the mouse hippocampus with neural stem cells that will mature and form new connections. In temporal lobe epilepsy, studies in adult rodents suggest that naturally occurring hippocampal neurogenesis is problematic. It seems that the newborn hippocampal neurons become highly excitable and contribute to seizures. We’re trying to inhibit these newborn hyperexcitable neurons with the transplants. But if humans don’t generate new hippocampal neurons, then maybe we’re developing a treatment in mice for a problem that has a different mechanism in people.
Perhaps our species has evolved separate mechanisms for neuroplasticity, distinct from those used by species such as rats and mice. One possibility is that there are other sites in the human brain where neurogenesis occurs - its a big structure and more exploration will be necessary. If it turns out to be true that the human brain has a diminished capacity for neurogenesis after birth, the finding will have important implications for how neuroscientists like me think about tackling brain disorders.
Perhaps most importantly, this work underscores how crucial it is to learn how to increase the longevity of the neurons we do have, born early in life, and how we might replace or repair neurons that become damaged.
Janice R. Naegele receives funding from the National Institutes of Health, Connecticut Regenerative Medicine Fund and CURE Epilepsy.
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Imposter Syndrome
Hannah Thompson, #IAmAWomanInSTEM student ambassador for Spring 2017, EXP 396: Dr. Hollingsworth
I was asked to choose one value that is important to me from a list of several common core values. Upon looking at the list, I began to realize how each of these played a crucial role in how I identified myself. However, the one that stood out to me the most was “Growth”. The growth of my knowledge, faith, and service is crucial to my identity. I find it incredibly important to pursue a career that challenges and allows one to obtain new knowledge as much as possible. That’s why I decided to pursue a career in STEM. However, I failed to realize the effect of the “confidence gap” and “imposter syndrome” on my female peers and mentors.
Imposter Syndrome affects individuals who feel as if they are not qualified for the work they are doing and fear being discovered as a fraud. The “confidence gap” plays a huge role in this concept. Studies show that women feel less qualified and self-assured as their male counterparts. I was shocked when I read The Atlantic’s article, “The Confidence Gap”. I quickly realized how often I doubted my own abilities and knowledge. The first time I scored below average on a chemistry test, I immediately began to think I wasn’t good enough. If I couldn’t get an A on this unit’s test, how could I possibly get an A in the course let alone keep a perfect GPA and get into Medical School? That one test shattered my scientific confidence, especially when I found out that one of my best friends, a boy, had scored much higher than me when he had studied probably half the time I had. Of course, we all wish there was a linear relationship between x amount of hours studied and our test score, but that’s not exactly how it works. Was he smarter than me? Was he simply just better at science than me? After reading this article, I noticed I wasn’t the only young woman who felt this way or asked questions of this nature.
Plenty of successful women have felt like an “imposter” in their field. Imposter Syndrome has even been identified by psychologists and its existence cannot be denied. I look around at my friends and realize many of us maintain a façade. A face, with which we show we are calm, happy, and relaxed. We don’t want someone else to know that we’re struggling in a class, even though we might be staying up until two a.m. to just catch up on what’s going on in class. I’ve had friends lie about their test scores just because they’re “embarrassed” or “ashamed”. However, one data point doesn’t create a trend. One bad test grade doesn’t define one’s scientific knowledge. Embarrassment and failures are necessary in order to succeed. But, even if one of my friends score an A on the next test they keep that achievement hidden. When I congratulate them on their grade I’ve heard responses, such as “Oh, it’s not a big deal. I just got lucky it wasn’t too hard.” Not only have I heard those responses, but I have also given them too. Women are more likely to credit their success to another individual or just pure luck. CathyCat wrote, “No matter how you got to where you are, someone believed that you could do the work, and you rose to the challenge and did it. It can be tricky to believe that you’ve earned your accomplishments but believe that you did the work. You have to have done it. Even if you had help, you contributed what you did, and that is not nothing.” I think it’s extremely important to give yourself credit where it’s due. I know that I have credited my success to other people in fear of being identified as a “know-it all” or even “arrogant”. However, there’s a fine line between arrogance and confidence. It’s especially important for our gender, to rise up and be proud of our achievements. I think I’ve always been proud of myself, however, just never wanted anyone else to know. Maybe it just took me these articles to realize that my success should be recognized. As a woman I am just as capable as the men in the room and if they’re able to share their achievements I should to. I am proud of my academic success, but as mentioned before it didn’t always come easy to me. I worked hard, studied for hours upon hours and wasn’t afraid to ask my instructor for help. Asking for help didn’t make me feel stupid, it made me feel proactive.
Women make up 48% of the workforce, but only 24% of the STEM workforce. If imposter syndrome and the confidence gap can be overcome I have no doubt women will rise in the STEM field. I’ve decided to be successful, I must be confident. I will not doubt myself just because someone else did better than me. I am not a fraud or imposter. I hope to grow these next few years in my scientific confidence. Science is my passion, my love, and what I consider to be an undeniable force in my past, present, and future. It is what I am and will always be.
Sources
Shipman, Katty Kay and Claire. "The Confidence Gap." The Atlantic. Atlantic Media Company, 26 Aug. 2015. Web. 02 Mar. 2017. http://www.theatlantic.com/magazine/archive/2014/05/the-confidence-gap/359815/.
CathyCat. "Never A Fraud: Combating Imposter Phenomenon." Tenure, She Wrote. 24 Feb. 2015. Web. 02 Mar. 2017. https://tenureshewrote.wordpress.com/2015/02/23/never-a-fraud-combating-imposter-phenomenon/.
"Faking It: Women, Academia, and Impostor Syndrome." Vitae, the online career hub for higher ed. 27 Mar. 2014. Web. 02 Mar. 2017. https://chroniclevitae.com/news/412-faking-it-women-academia-and-impostor-syndrome
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