Chapter 13. Memory, Learning, and Development
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By Mitch Leslie Identical twins may be alike in everything from their eye color to their favorite foods, but they can diverge in one important characteristic: their weight. A new study uncovers a molecular mechanism for obesity that might explain why one twin can be extremely overweight even while the other is thin. Heredity influences whether we become obese, but the genes researchers have linked to the condition don’t explain many of the differences in weight among people. Identical twins with nonidentical weights are a prime example. So what accounts for the variation? Changes in the intestinal microbiome—the collection of bacteria living in the gut—are one possibility. Another is epigenetic changes, or alterations in gene activity. These changes occur when molecules latch on to DNA or the proteins it wraps around, turning sets of genes “on” or “off.” Triggered by factors in the environment, epigenetic modifications can be passed down from one generation to the next. This type of transmission happened during the Hunger Winter, a famine that occurred when the Germans cut off food supplies to parts of the Netherlands in the final months of World War II. Mothers who were pregnant during the famine gave birth to children who were prone to obesity decades later, suggesting that the mothers’ diets had a lasting impact on their kids’ metabolism. However, which epigenetic changes in people promote obesity remains unclear. © 2016 American Association for the Advancement of Science
By BENEDICT CAREY Scientists reported on Wednesday that they had taken a significant step toward understanding the cause of schizophrenia, in a landmark study that provides the first rigorously tested insight into the biology behind any common psychiatric disorder. More than two million Americans have a diagnosis of schizophrenia, which is characterized by delusional thinking and hallucinations. The drugs available to treat it blunt some of its symptoms but do not touch the underlying cause. The finding, published in the journal Nature, will not lead to new treatments soon, experts said, nor to widely available testing for individual risk. But the results provide researchers with their first biological handle on an ancient disorder whose cause has confounded modern science for generations. The finding also helps explain some other mysteries, including why the disorder often begins in adolescence or young adulthood. “They did a phenomenal job,” said David B. Goldstein, a professor of genetics at Columbia University who has been critical of previous large-scale projects focused on the genetics of psychiatric disorders. “This paper gives us a foothold, something we can work on, and that’s what we’ve been looking for now, for a long, long time.” The researchers pieced together the steps by which genes can increase a person’s risk of developing schizophrenia. That risk, they found, is tied to a natural process called synaptic pruning, in which the brain sheds weak or redundant connections between neurons as it matures. During adolescence and early adulthood, this activity takes place primarily in the section of the brain where thinking and planning skills are centered, known as the prefrontal cortex. People who carry genes that accelerate or intensify that pruning are at higher risk of developing schizophrenia than those who do not, the new study suggests. Some researchers had suspected that the pruning must somehow go awry in people with schizophrenia, because previous studies showed that their prefrontal areas tended to have a diminished number of neural connections, compared with those of unaffected people. © 2016 The New York Times Company
By Ellen Hendriksen This topic comes by request on the Savvy Psychologist Facebook page from listener Anita M. of Detroit. Anita works with foster kids and, too often, sees disadvantaged kids who have been on a cocktail of psychiatric medications from as early as age 6. She asks, does such early use alter a child’s brain or body? And have the effects of lifelong psychiatric medication been studied? Childhood mental illness (and resulting medication) is equally overblown and under-recognized. Approximately 21% of American kids - that’s 1 in 5 - will battle a diagnosable mental illness before they reach the age of 17, whether or not they actually get treatment. The problem is anything but simple. Some childhood illnesses - ADHD and autism, for example - often get misused as “grab-bag” diagnoses when something’s wrong but no one knows what. This leads to overdiagnosis and sometimes, overmedicating. Other illnesses, like substance abuse, get overlooked or written off as rebellion or experimentation, leading to underdiagnosis and kids slipping through the cracks. But the most common problem is inconsistent diagnosis. For example, a 2008 study found that fewer than half of individuals diagnosed with bipolar disorder actually had the illness, while 5% of those diagnosed with something completely different actually had bipolar disorder. But let’s get back to Anita’s questions: Does early psychotropic medication alter a child’s brain? The short answer is yes, but the long answer might be different than you think. © 2016 Scientific American
Nell Greenfieldboyce The state of New Jersey has been trying to help jurors better assess the reliability of eyewitness testimony, but a recent study suggests that the effort may be having unintended consequences. That's because a new set of instructions read to jurors by a judge seems to make them skeptical of all eyewitness testimony — even testimony that should be considered reasonably reliable. Back in 2012, New Jersey's Supreme Court did something groundbreaking. It said that in cases that involve eyewitness testimony, judges must give jurors a special set of instructions. The instructions are basically a tutorial on what scientific research has learned about eyewitness testimony and the factors that can make it more dependable or less so. "The hope with this was that jurors would then be able to tell what eyewitness testimony was trustworthy, what sort wasn't, and at the end of the day it would lead to better decisions, better court outcomes, better justice," says psychologist David Yokum. Yokum was a graduate student at the University of Arizona, doing research on decision-making, when he and two colleagues, Athan Papailiou and Christopher Robertson, decided to test the effect of these new jury instructions, using videos of a mock trial that they showed to volunteers. © 2016 npr
Keyword: Learning & Memory
Link ID: 21828 - Posted: 01.27.2016
James Gorman Spotted hyenas are the animals that got Sarah Benson-Amram thinking about how smart carnivores are and in what ways. Dr. Benson-Amram, a researcher at the University of Wyoming in Laramie, did research for her dissertation on hyenas in the wild under Kay E. Holekamp of Michigan State University. Hyenas have very complicated social structures and they require intelligence to function in their clans, or groups. But the researchers also tested the animals on a kind of intelligence very different from figuring out who ranks the highest: They put out metal boxes that the animals had to open by sliding a bolt in order to get at meat inside. Only 15 percent of the hyenas solved the problem in the wild, but in captivity, the animals showed a success rate of 80 percent. Dr. Benson-Amram and Dr. Holekamp decided to test other carnivores, comparing species and families. They and other researchers presented animals in several different zoos with a metal puzzle box with a treat inside and recorded the animals’ efforts. They tested 140 animals in 39 species that were part of nine families. They reported their findings on Monday in the Proceedings of the National Academy of Sciences. They compared the success rates of different families with absolute brain size, relative brain size, and the size of the social groups that the species form in the wild. Just having a bigger brain did not make difference, but the relative size of the brain, compared with the size of the body, was the best indication of which animals were able to solve the problem of opening the box. © 2016 The New York Times Company
Ian Sample Science editor Genetically modified (GM) monkeys that develop symptoms of autism have been created to help scientists discover treatments for the condition. The macaques carry a genetic fault that causes a rare disorder in humans called MeCP2 duplication syndrome. This produces a wide range of medical conditions, some of which mirror those seen in autism, such as difficulties with social interactions. Researchers say groups of the GM monkeys could be used to identify brain circuits involved in common autistic behaviours and to test new treatments designed to alleviate the symptoms. Because the monkeys pass the genetic defects on to their offspring, scientists can breed large populations of the animals for medical research. A group of 200 monkeys has been established at the scientists’ lab in China. The research, described in the journal Nature, paves the way for more varieties of GM monkeys that develop different mental and psychiatric problems which are almost impossible to study in other animals. “The first cohort of transgenic monkeys shows very similar behaviour to human autism, including increased anxiety, but most importantly, defects in social interactions,” said Zilong Qiu who led the research at the Institute of Neuroscience in Shanghai. © 2016 Guardian News and Media Limited or it
Alison Abbott For the second time in four months, researchers have reported autopsy results that suggest Alzheimer’s disease might occasionally be transmitted to people during certain medical treatments — although scientists say that neither set of findings is conclusive. The latest autopsies, described in the Swiss Medical Weekly1 on 26 January, were conducted on the brains of seven people who died of the rare, brain-wasting Creutzfeldt–Jakob disease (CJD). Decades before their deaths, the individuals had all received surgical grafts of dura mater — the membrane that covers the brain and spinal cord. These grafts had been prepared from human cadavers and were contaminated with the prion protein that causes CJD. But in addition to the damage caused by the prions, five of the brains displayed some of the pathological signs that are associated with Alzheimer’s disease, researchers from Switzerland and Austria report. Plaques formed from amyloid-β protein were discovered in the grey matter and blood vessels. The individuals, aged between 28 and 63, were unusually young to have developed such plaques. A set of 21 controls, who had not had surgical grafts of dura mater but died of sporadic CJD at similar ages, did not have this amyloid signature. According to the authors, it is possible that the transplanted dura mater was contaminated with small ‘seeds’ of amyloid-β protein — which some scientists think could be a trigger for Alzheimer’s — along with the prion protein that gave the recipients CJD. © 2016 Nature Publishing Group,
By Esther Landhuis Amid gloomy reports of an impending epidemic of Alzheimer’s and other dementias, emerging research offers a promising twist. Recent studies in North America, the U.K. and Europe suggest that dementia risk among seniors in some high-income countries has dropped steadily over the past 25 years. If the trend is driven by midlife factors such as building “brain reserve” and maintaining heart health, as some experts suspect, this could lend credence to staying mentally engaged and taking cholesterol-lowering drugs as preventive measures. At first glance, the overall message seems somewhat confusing. Higher life expectancy and falling birth rates are driving up the global elderly population. “And if there are more 85-year-olds, it’s almost certain there will be more cases of age-related diseases,” says Ken Langa, professor of internal medicine at the University of Michigan. According to the World Alzheimer Report 2015 (pdf), 46.8 million people around the globe suffered from dementia last year, and that number is expected to double every 20 years. Looking more closely, though, new epidemiological studies reveal a surprisingly hopeful trend. Analyses conducted over the last decade in the U.S., Canada, England, the Netherlands, Sweden and Denmark suggest that “a 75- to 85-year-old has a lower risk of having Alzheimer’s today than 15 or 20 years ago,” says Langa, who discussed the research on falling dementia rates in a 2015 Alzheimer’s Research & Therapy commentary (pdf). © 2016 Scientific America
Link ID: 21821 - Posted: 01.26.2016
by Graham McDougall, Jr., behavioral scientist at U. of Alabama Chemo brain is a mental cloudiness reported by about 30 percent of cancer patients who receive chemotherapy. Symptoms typically include impairments in attention, concentration, executive function, memory and visuospatial skills. Since the 1990s researchers have tried to understand this phenomenon, particularly in breast cancer patients. But the exact cause of chemo brain remains unclear. Some studies indicate that chemotherapy may trigger a variety of related neurological symptoms. One study, which examined the effects of chemotherapy in 42 breast cancer patients who underwent a neuropsychological evaluation before and after treatment, found that almost three times more patients displayed signs of cognitive dysfunction after treatment as compared with before (21 versus 61 percent). A 2012 review of 17 studies considering 807 breast cancer patients found that cognitive changes after chemotherapy were pervasive. Other research indicates that the degree of mental fogginess that a patient experiences may be directly related to how much chemotherapy that person receives: higher doses lead to greater dysfunction. There are several possible mechanisms to explain the cognitive changes associated with chemotherapy treatments. The drugs may have direct neurotoxic effects on the brain or may indirectly trigger immunological responses that may cause an inflammatory reaction in the brain. Chemotherapy, however, is not the only possible culprit. Research also shows that cancer itself may cause changes to the brain. In addition, it is possible that the observed cognitive decline may simply be part of the natural aging process, especially considering that many cancer patients are older than 50 years. © 2016 Scientific American,
By David Shultz A rat navigating a maze has to rank somewhere near the top of science tropes. Now, scientists report that they’ve developed an analogous test for humans—one that involves driving through a virtual landscape in a simulated car. The advance, they say, may provide a more sensitive measure for detecting early signs of Alzheimer’s disease. “I think it’s a very well-done study,” says Keith Vossel, a translational neuroscientist at the University of California, San Francisco (UCSF), who was not involved with the work. In the rodent version of the so-called Morris Maze Test, researchers fill a large cylindrical container with water and place a platform just above the waterline. A scientist then places a rat into the tank, and the rodent must swim to the platform to avoid drowning. The experimenter then raises the water level just above the height of the platform and adds a compound to the water to make it opaque. The trial is repeated, but now the rat must find the platform without seeing it, using only its memory of where the safe zone exists relative to the tank’s walls and the surrounding environment. In subsequent trials, researchers place the rat at different starting points along the tank’s edge, but the platform stays put. In essence, the task requires the rat to move to a specific but invisible location within a circular arena from different starting points. © 2016 American Association for the Advancement of Science.
Link ID: 21803 - Posted: 01.20.2016
By Emily Underwood Roughly half of Americans use marijuana at some point in their lives, and many start as teenagers. Although some studies suggest the drug could harm the maturing adolescent brain, the true risk is controversial. Now, in the first study of its kind, scientists have analyzed long-term marijuana use in teens, comparing IQ changes in twin siblings who either used or abstained from marijuana for 10 years. After taking environmental factors into account, the scientists found no measurable link between marijuana use and lower IQ. “This is a very well-conducted study … and a welcome addition to the literature,” says Valerie Curran, a psychopharmacologist at the University College London. She and her colleagues reached “broadly the same conclusions” in a separate, nontwin study of more than2000 British teenagers, published earlier this month in the Journal of Psychopharmacology, she says. But, warning that the study has important limitations, George Patton, a psychiatric epidemiologist at the University of Melbourne in Australia, adds that it in no way proves that marijuana—particularly heavy, or chronic use —is safe for teenagers. Most studies that linked marijuana to cognitive deficits, such as memory loss and low IQ, looked at a single “snapshot” in time, says statistician Nicholas Jackson of the University of Southern California in Los Angeles, lead author of the new work. That makes it impossible to tell which came first: drug use or poor cognitive performance. “It's a classic chicken-egg scenario,” he says. © 2016 American Association for the Advancement of Science.
By DONALD G. McNEIL Jr. Federal health officials on Friday advised pregnant women to postpone traveling to 13 Latin American or Caribbean countries and Puerto Rico where mosquitoes are spreading the Zika virus, which has been linked to brain damage in babies. Women considering becoming pregnant were advised to consult doctors before traveling to countries with Zika cases, and all travelers were urged to avoid mosquito bites, as were residents of Puerto Rico and the United States Virgin Islands. “We believe this is a fairly serious problem,” said Dr. Lyle R. Petersen, chief of vector-borne diseases for the Centers for Disease Control and Prevention. “This virus is spreading throughout the Americas. We didn’t feel we could wait.” The C.D.C. advisory applies to 14 Western Hemisphere countries and territories: Brazil, Colombia, El Salvador, French Guiana, Guatemala, Haiti, Honduras, Martinique, Mexico, Panama, Paraguay, Suriname, Venezuela, and the Commonwealth of Puerto Rico. It applies to the entire countries “unless there is specific evidence the virus is not occurring somewhere,” Dr. Petersen said. This appears to be the first time the Centers for Disease Control and Prevention has advised pregnant women to avoid a specific region. The warning is expected to affect the travel industry and could affect the Summer Olympics, set for Brazil in August. Officials at Brazil’s Health Ministry were not available for comment Friday night. Hours earlier, Philip Wilkinson, a spokesman for the Rio 2016 organizing committee, said that Olympic venues “will be inspected on daily basis during the Rio 2016 Games to ensure there are no puddles of stagnant water and therefore minimize the risk of coming into contact with mosquitos.” Dr. Petersen said he did not want to speculate about how his agency’s warning might affect the Olympics. “This is a dynamic situation,” he said. “We’re going to wait and see how this all plays out. Viruses can spread in a population for some periods of time.” © 2016 The New York Times Company
Keyword: Development of the Brain
Link ID: 21792 - Posted: 01.16.2016
Laura Beil When Elinor Sullivan was a postdoctoral fellow at Oregon Health & Science University in Portland, she set out to explore the influence of food and exercise habits on obesity. In one experiment, she and her colleagues fed a troop of macaque monkeys regular chow. Other macaques dined American-style, with a hefty 32 percent of calories from fat and ready access to peanut butter treats. Over time, the second group of monkeys grew noticeably fatter. Then they all had babies. Sullivan, now at the University of Portland, noticed odd behavior in the plump moms’ offspring. At playtime, they often slinked off by themselves. When handled by keepers, the infants tended to vocalize anxiously, and the males became aggressive. They were prone to repetitive habits, like pacing. In their carefully controlled world, the only difference between those monkeys and others at the facility was their mothers’ extra pounds and indulgent diet. The behavior was so striking that Sullivan changed the course of her research. “It made me start thinking about human children,” she says, and the twin epidemics of obesity and behavioral problems such as attention-deficit/hyperactivity disorder. Her research, published in 2010 in the Journal of Neuroscience, was one of the first studies to note that the progeny of female monkeys eating a high-fat diet were more likely to experience altered brain development and suffer anxiety. Not long after, researchers worldwide began compiling evidence linking the heaviness of human mothers to mental health in their children. One headline-grabbing study of more than 1,000 births, reported in 2012, found that autism spectrum disorders showed up more often in children of obese mothers than in normal-weight women (SN: 5/19/12, p. 16). © Society for Science & the Public 2000 - 2015.
Laura Sanders Pain can sear memories into the brain, a new study finds. A full year after viewing a picture of a random, neutral object, people could remember it better if they had been feeling painful heat when they first saw it. “The results are fun, they are interesting and they are provocative,” says neuroscientist A. Vania Apkarian of Northwestern University in Chicago. The findings “speak to the idea that pain really engages memory.” Neuroscientists G. Elliott Wimmer and Christian Büchel of University Medical Center Hamburg-Eppendorf in Germany reported the results in a paper online at BioRxiv.org first posted December 24 and revised January 6. The findings are under review at a journal, and Wimmer declined to comment on the study until it is accepted for publication. Wimmer and Büchel recruited 31 brave souls who agreed to feel pain delivered by a heat-delivering thermode on their left forearms. Each person’s pain sensitivity was used to calibrate the amount of heat they received in the experiment, which was either not painful (a 2 on an 8-point scale) or the highest a person could endure multiple times (a full 8). While undergoing a functional MRI scan, participants looked at a series of pictures of unremarkable household objects, such as a camera, sometimes feeling pain and sometimes not. Right after seeing the images, the people took a pop quiz in which they answered whether an object was familiar. Pain didn’t influence memory right away. Right after their ordeal, participants remembered about three-quarters of the previously seen objects, regardless of whether pain was present, the researchers found. © Society for Science & the Public 2000 - 2015.
by Laura Sanders Young babies get a bad rap. They’re helpless, fickle and noisy. And even though they allegedly sleep for 16 hours a day, those hours come in 20-minute increments. Yet hidden in the chaos of a young infant’s life are some truly magnificent skills — perceptual feats that put adults to shame. So next time your baby loses it because she can’t get her thumb into her mouth, keep in mind that her strengths lie elsewhere. Six-month-old babies can spot subtle differences between two monkey faces easy as pie. But 9-month-olds — and adults — are blind to the differences. In a 2002 study of facial recognition, scientists pitted 30 6-month-old babies against 30 9-month-olds and 11 adults. First, the groups got familiar with a series of monkey and human faces that flashed on a screen. Then new faces showed up, interspersed with already familiar faces. The idea is that the babies would spend more time looking at new faces than ones they had already seen. When viewing human faces, all of the observers, babies and adults alike, did indeed spend more time looking at the new people, showing that they could easily pick out familiar human faces. But when it came to recognizing monkey faces, the youngsters blew the competition out of the water. Six-month-old babies recognized familiar monkey faces and stared at the newcomers longer. But both adults and 9-month-old babies were flummoxed, and looked at the new and familiar monkey faces for about the same amount of time. © Society for Science & the Public 2000 - 2015
Blocking the production of new immune cells in the brain could reduce memory problems seen in Alzheimer's disease, a study suggests. University of Southampton researchers said their findings added weight to evidence that inflammation in the brain is what drives the disease. A drug used to block the production of these microglia cells in the brains of mice had a positive effect. Experts said the results were exciting and could lead to new treatments. Up until now, most drugs used to treat dementia have targeted amyloid plaques in the brain which are a characteristic of people with the Alzheimer's disease. But this latest study, published in the journal Brain, suggests that in fact targeting inflammation in the brain, caused by a build-up of immune cells called microglia, could halt progression of the disease. Researchers found increased numbers of microglia in the post-mortem brains of people with Alzheimer's disease. Previous studies have also suggested that these cells could play an important role. Dr Diego Gomez-Nicola, lead study author from the university, said: "These findings are as close to evidence as we can get to show that this particular pathway is active in the development of Alzheimer's disease. "The next step is to work closely with our partners in industry to find a safe and suitable drug that can be tested to see if it works in humans." © 2016 BBC
By Emily Underwood Lumos Labs, the company that produces the popular “brain-training” program Lumosity, yesterday agreed to pay a $2 million settlement to the Federal Trade Commission (FTC) for running deceptive advertisements. Lumos had claimed that its online games can help users perform better at work and in school and stave off cognitive deficits associated with serious diseases such as Alzheimer’s, traumatic brain injury, and post-traumatic stress. The $2 million settlement will be used to compensate Lumosity consumers who were misled by false advertising, says Michelle Rusk, a spokesperson with FTC in Washington, D.C. The company will also be required to provide an easy way to cancel autorenewal billing for the service, which includes online and mobile app subscriptions, with payments ranging from $14.95 monthly to lifetime memberships for $299.95. Before consumers can access the games, a pop-up screen will alert them to FTC’s order and allow them to avoid future billing, Rusk says. The action is part of a larger crackdown on companies selling products that purportedly enhance memory or provide some other cognitive benefit, Rusk says. For some time now, FTC has been “concerned about some of the claims we’re seeing out there,” particularly those from companies like Lumos that suggest their games can reduce the effects of conditions such as dementia, she says. After evaluating the literature on Lumos's products, and the broader research on the benefits of brain-training games, “our assessment was they didn’t have adequate science for the claims that they’re making,” she says. © 2016 American Association for the Advancement of Science
Katherine Hobson Pregnant women worry about all kinds of things. Can I drink alcohol? (No.) Can I take antidepressants? (Maybe.) Can I do the downward dog? (Yes.) Now there's one less thing to fret about: harm to the baby when the mother takes birth control pill right before conceiving, or during the first few months of pregnancy. According to a study covering more than 880,000 births in Denmark, the overall rate of birth defects was consistent for women who had never taken the pill at all, for those who had used it before getting pregnant and for those who continued on the pill in early pregnancy. (There were about 25 birth defects per 1,000 births for all groups.) The study is important because so many women take the pill – about 16 percent of women of childbearing age in the U.S. When used perfectly, the failure rate of the pill is less than 1 percent, but that jumps to 9 percent under typical use because of missed pills, drug interactions or illness. That means a lot of embryos are exposed to the hormones used in the pill, which can linger for a few months after a woman stops taking it. "Our findings are really reassuring," says Brittany Charlton, an author of the study and a researcher in the Harvard T.H. Chan School of Public Health's epidemiology department. The results also confirm most of the previous research, which has pointed to no overall increase in major birth defects, she says. This study, published in the medical journal BMJ, used national birth, patient and prescription registry data to track contraceptive prescriptions among women who gave birth, then looked at whether birth defects were associated with pill use. © 2016 npr
Children conceived via infertility treatments are no more likely to have a developmental delay than children conceived without such treatments, according to a study by researchers at the National Institutes of Health, the New York State Department of Health and other institutions. The findings, published online in JAMA Pediatrics, may help to allay longstanding concerns that conception after infertility treatment could affect the embryo at a sensitive stage and result in lifelong disability. The authors found no differences in developmental assessment scores of more than 1,800 children born to women who became pregnant after receiving infertility treatment and those of more than 4,000 children born to women who did not undergo such treatment. “When we began our study, there was little research on the potential effects of conception via fertility treatments on U.S. children,” said Edwina Yeung, Ph.D., an investigator in the Division of Intramural Population Health Research at NIH’s Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD). “Our results provide reassurance to the thousands of couples who have relied on these treatments to establish their families.” Also taking part in the study were researchers from the University at Albany, New York; the New York State Department of Health, also in Albany; and CapitalCare Pediatrics in Troy, New York. The Upstate KIDS study enrolled infants born to women in New York State (except for New York City) from 2008 to 2010. Parents of infants whose birth certificates indicated infertility treatment were invited to enroll their children in the study, as were all parents of twins and other multiples. The researchers also recruited roughly three times as many singletons not conceived via infertility treatment. Four months after giving birth, the mothers indicated on a questionnaire the type of infertility treatment they received:
Keyword: Development of the Brain
Link ID: 21755 - Posted: 01.07.2016
Laura Sanders It didn’t take a lot of brainpower to come up with the name for a nerve cell that looks like a bushy, round tangle of fibers perched atop a nucleus. Meet the shrub cell. This botanically named cell, discovered in the brains of adult mice, made its formal debut in the Nov. 27 Science. The newly described cell lives in a particular nervy neighborhood — an area called layer 5 in the part of the brain that handles incoming visual information. Xiaolong Jiang of Baylor College of Medicine in Houston and colleagues defined shrub cells and other newcomers by their distinct shapes, their particular connections to other nerve cells or their similarities to nerve cells found elsewhere. Joining shrub cells are the freshly named horizontally elongated cells, deep-projecting cells, L5 basket cells and L5 neurogliaform cells. Each is an interneuron, a middleman that connects nerve cells to each other. The finding highlights the stunning variety of shapes and wiring patterns of cells in the brain. Citations X. Jiang et al. Principles of connectivity among morphologically defined cell types in adult neocortex. Science. Vol. 350, November 27, 2015. doi: 10.1126/science.aac9462 © Society for Science & the Public 2000 - 2015.
Keyword: Development of the Brain
Link ID: 21754 - Posted: 01.07.2016