By Allison Hirschlag Everyone likes a good nap now and then, right? Whether you nod off during a boring movie, or rest your head on your desk at work for 20 minutes or so to fight the afternoon slump, naps can revitalize you in a major way. One study even showed they can boost performance and memory regulation better than caffeine. This all sounds great in theory, but many people — myself included — find naps do the opposite. I wake up from naps feeling like I’m in the throes of a New Year’s Day-strength hangover. It takes me at least 20 minutes to recover from them, and I never end up seeing any of the benefits. Even when I timed my nap to be no more than 30 minutes — the nap length sleep experts claim is the most beneficial — I came out of it certain I was experiencing the early stages of the flu (I wasn’t). Naturally, I’ve always been a little jealous of the people who take naps and wake up feeling like a million bucks. I’m a healthy, youngish, childless woman who regularly sleeps seven to eight hours a night — why don’t naps work for me? The short answer is that some adults are genetically predisposed to need more hours of continuous sleep than others (I’m leaving children out of this because, as growing bodies, they naturally need more sleep). According to a study by the National Heart, Lung and Blood Institute, at least 80 genes appear to be involved in sleep regulation, which “suggests that sleep duration in natural populations can be influenced by a wide variety of biological processes.” Simply put, sleep duration needs vary considerably because they’re based on a broad spectrum of genetic differences.

Keyword: Sleep; Genes & Behavior
Link ID: 27105 - Posted: 03.09.2020

By Heather Jones I knew early on that my normal didn’t feel like everyone else’s. Even as early as kindergarten, I could tell that my brain worked differently than others, and that I seemed more listless than other children my age. Other kids felt sadness when they experienced a loss or something upsetting. I always felt sad. I didn’t question the cloudy lens through which I viewed the world, because I had never seen clearly. When I was 16, my family doctor asked me the questions that would change my worldview. Having treated me since childhood, she had noticed patterns. She asked me whether I was experiencing the list of symptoms associated with persistent depressive disorder. I had all of them — feeling down, feeling hopeless, sleep problems, avoidance of social activities, low self-esteem and the rest of the laundry list of warning signs. My doctor explained to me that persistent depressive disorder, also called dysthymia, was a type of “functional depression” that lasts for years and often for a lifetime. I had probably had it since early childhood. I burst into tears, finally knowing there was a reason I felt this way. Knowing what I had didn’t take away my depression — more than 20 years later, I am still living with this condition — but getting a proper diagnosis started me on a path to better management of my symptoms. I am not alone. According to the National Institute of Mental Health, 1.3 percent of American adults will experience persistent depressive disorder at some time in their lives.

Keyword: Depression
Link ID: 27104 - Posted: 03.09.2020

Amelia Hill A low carbohydrate diet may prevent and even reverse age-related damage to the brain, research has found. By examining brain scans, researchers found that brain pathways begin to deteriorate in our late 40s – earlier than was believed. “Neurobiological changes associated with ageing can be seen at a much younger age than would be expected, in the late 40s,” said Lilianne R Mujica-Parodi, a professor in the department of biomedical engineering at Stony Brook University in New York. “However, the study also suggests that this process may be prevented or reversed based on dietary changes that involve minimising the consumption of simple carbohydrates,” added Mujica-Parodi. To better understand how diet influences brain ageing, researchers concentrated on young people whose brains showed no signs of ageing. This is the period during which prevention may be most effective. Using brain scans of nearly 1,000 individuals between the ages of 18 to 88, researchers found that the damage to neural pathways accelerated depending on where the brain was getting its energy from. Glucose, they found, decreased the stability of the brain’s networks while ketones – produced by the liver during periods of carbohydrate restrictive diets – made the networks more stable. “What we found with these experiments involves both bad and good news,” said Mujica-Parodi, “The bad news is that we see the first signs of brain ageing much earlier than was previously thought. “However, the good news is that we may be able to prevent or reverse these effects with diet … by exchanging glucose for ketones as fuel for neurons,” she added in the study, which is published in PNAS. © 2020 Guardian News & Media Limited

Keyword: Alzheimers; Obesity
Link ID: 27103 - Posted: 03.07.2020

Dori Grijseels In 2016, three neuroscientists wrote a commentary article arguing that, to truly understand the brain, neuroscience needed to change. From that paper, the International Brain Laboratory (IBL) was born. The IBL, now a collaboration between 22 labs across the world, is unique in biology. The IBL is modeled on physics collaborations, like the ATLAS experiment at CERN, where thousands of scientists work together on a common problem, sharing data and resources during the process. This was in response to the main criticism that the paper’s authors, Zachary Mainen, Michael Häusser and Alexandre Pouget, had about existing neuroscience collaborations: labs came together to discuss generalities, but all the experiments were done separately. They wanted to create a collaboration in which scientists worked together throughout the process, even though their labs may be distributed all over the globe. The IBL decided to focus on one brain function only: decision-making. Decision-making engages the whole brain, since it requires using both input from the senses and information about previous experiences. If someone is thinking about bringing a sweater when they go out, they will use their senses to determine whether it looks and feels cold outside, but they might also remember that, yesterday, they were cold without a sweater. For its first published (in pre-print form) experiment, seven labs of the 22 collaborating in the IBL tested 101 mice on their decision-making ability. The mice saw a black and white grating either to their right or to their left. They then had to twist a little Lego wheel to move the grating to the middle. By rewarding them with sugary water whenever they did the task correctly, the mice gradually learned. It is easy for them to decide which way to twist the wheel if the grating has a high contrast, because it stands out compared to the background of their visual field. However, the mice were also presented with a more ambiguously-patterned grating not easily distinguishable from the background, so the decision of which way to turn the wheel was more difficult. In some cases, the grating was even indistinguishable from the background. Between all seven labs –which were spread across three countries – the mice completed this task three million times. © 2017 – 2019 Massive Science Inc.

Keyword: Attention; Learning & Memory
Link ID: 27102 - Posted: 03.07.2020

By Liz Langley It might be time to reconsider what it means to call someone a “rat.” Previous research has shown the much-maligned rodents assist comrades in need, as well as remember individual rats that have helped them—and return the favor. Now, a new study builds on this evidence of empathy, revealing that domestic rats will avoid harming other rats. In the study, published March 5 in the journal Current Biology, rats were trained to pull levers to get a tasty sugar pellet. If the lever delivered a mild shock to a neighbor, several of the rats stopped pulling that lever and switched to another. Harm aversion, as it's known, is a well-known human trait regulated by a part of the brain called the anterior cingulate cortex (ACC). Further experiments showed the ACC controls this behavior in rats, too. This is the first time scientists have found the ACC is necessary for harm aversion in a non-human species. This likeness between human and rat brains is “super-exciting for two reasons,” says study co-author Christian Keysers, of the Netherlands Institute for Neuroscience. For one, it suggests that preventing harm to others is rooted deep in mammals' evolutionary history. (See what a rat looks like when it’s happy.) What’s more, the finding could have a real impact on people suffering from psychiatric disorders such as psychopathy and sociopathy, whose anterior cingulate cortexes are impaired. “We currently have no effective drugs to reduce violence in antisocial populations,” Keysers says, and figuring out how to increase such patients’ aversion to hurting others could be a powerful tool.

Keyword: Attention; Emotions
Link ID: 27101 - Posted: 03.07.2020

Heidi Ledford A person with a genetic condition that causes blindness has become the first to receive a CRISPR–Cas9 gene therapy administered directly into their body. The treatment is part of a landmark clinical trial to test the ability of CRISPR–Cas9 gene-editing techniques to remove mutations that cause a rare condition called Leber’s congenital amaurosis 10 (LCA10). No treatment is currently available for the disease, which is a leading cause of blindness in childhood. For the latest trial, the components of the gene-editing system – encoded in the genome of a virus — are injected directly into the eye, near photoreceptor cells. By contrast, previous CRISPR–Cas9 clinical trials have used the technique to edit the genomes of cells that have been removed from the body. The material is then infused back into the patient. “It’s an exciting time,” says Mark Pennesi, a specialist in inherited retinal diseases at Oregon Health & Science University in Portland. Pennesi is collaborating with the pharmaceutical companies Editas Medicine of Cambridge, Massachusetts, and Allergan of Dublin to conduct the trial, which has been named BRILLIANCE. This is not the first time gene editing has been tried in the body: an older gene-editing system, called zinc-finger nucleases, has already been administered directly into people participating in clinical trials. Sangamo Therapeutics of Brisbane, California, has tested a zinc-finger-based treatment for a metabolic condition called Hunter’s syndrome. The technique inserts a healthy copy of the affected gene into a specific location in the genome of liver cells. Although it seems to be safe, early results suggest it might do little to ease the symptoms of Hunter’s syndrome. © 2020 Springer Nature Limited

Keyword: Vision; Genes & Behavior
Link ID: 27100 - Posted: 03.06.2020

By Michael Price Every Fourth of July, the thunderous crack of my neighbors’ fireworks is quickly followed by the wailing chorus of frightened dogs, including my own two mixed-breed pups. New research suggests Pico’s and Winnie’s sensitivity to noise, especially fireworks, is the most common form of anxiety in pet dogs. The study—the largest ever on canine temperaments—also finds that some breeds are prone to certain anxious behaviors, including aggression, separation anxiety, and fear. The results could help uncover new ways to tackle these traits. Anecdotes on dog behavior abound, but reliable scientific data are lacking, says Hannes Lohi, a canine geneticist at the University of Helsinki. That’s particularly an issue when looking at problem behaviors that can put dogs at higher risk of being euthanized or winding up in shelters. So Lohi and colleagues contacted Finnish dog breed clubs and reached out to dog owners around the world through social media, asking owners to rate their dogs’ behavior on seven different anxiety-related traits: noise sensitivity, general fear, fear of heights and surfaces (like reflective tiles), inattention, compulsive behaviors (like relentless chewing or tail chasing), aggression, and separation anxiety. They received more than 13,700 responses representing 264 breeds. To make reliable comparisons, the researchers limited themselves to the 14 breeds with 200 or more surveyed dogs. © 2020 American Association for the Advancement of Science.

Keyword: Emotions; Genes & Behavior
Link ID: 27099 - Posted: 03.06.2020

In a study of epilepsy patients, researchers at the National Institutes of Health monitored the electrical activity of thousands of individual brain cells, called neurons, as patients took memory tests. They found that the firing patterns of the cells that occurred when patients learned a word pair were replayed fractions of a second before they successfully remembered the pair. The study was part of an NIH Clinical Center trial for patients with drug-resistant epilepsy whose seizures cannot be controlled with drugs. “Memory plays a crucial role in our lives. Just as musical notes are recorded as grooves on a record, it appears that our brains store memories in neural firing patterns that can be replayed over and over again,” said Kareem Zaghloul, M.D., Ph.D., a neurosurgeon-researcher at the NIH’s National Institute of Neurological Disorders and Stroke (NINDS) and senior author of the study published in Science. Dr. Zaghloul’s team has been recording electrical currents of drug-resistant epilepsy patients temporarily living with surgically implanted electrodes designed to monitor brain activity in the hopes of identifying the source of a patient’s seizures. This period also provides an opportunity to study neural activity during memory. In this study, his team examined the activity used to store memories of our past experiences, which scientists call episodic memories. In 1957, the case of an epilepsy patient H.M. provided a breakthrough in memory research. H.M could not remember new experiences after part of his brain was surgically removed to stop his seizures. Since then, research has pointed to the idea that episodic memories are stored, or encoded, as neural activity patterns that our brains replay when triggered by such things as the whiff of a familiar scent or the riff of a catchy tune. But exactly how this happens was unknown.

Keyword: Learning & Memory
Link ID: 27098 - Posted: 03.06.2020

Katarina Zimmer Long believed to be simple, pathogen-eating immune cells, macrophages have a far more extensive list of job duties. They appear to have specialized functions across body tissues, help repair damaged tissue, play a key role in regulating inflammation and pain, and participate in other roles scientists are just beginning to reveal. Now, a group of researchers in the Netherlands has identified a mechanism by which macrophages may help resolve inflammatory pain in mice. In a study recently posted as a preprint to bioRxiv, they report that the immune cells shuttle mitochondria to sensory neurons that innervate inflamed tissue, and that this helps resolve pain. The researchers speculate that the mechanism could replenish functional mitochondria in neurons during chronic inflammatory conditions, which is associated with dysfunctional mitochondria. “I think the transfer of mitochondria is quite convincing,” Jan Van den Bossche, an immunologist at Amsterdam University Medical Center who wasn’t involved in the research, writes to The Scientist in an email. If the findings can be replicated, “this could have [implications for] many diseases with chronic inflammation and pain,” he adds. The research is the result of a five-year project that began when Niels Eijkelkamp, a neuroimmunologist at the University Medical Center Utrecht, and his colleagues started investigating how inflammatory pain resolves, “so we could understand what causes chronic pain,” he says. © 1986–2020 The Scientist

Keyword: Glia; Pain & Touch
Link ID: 27097 - Posted: 03.06.2020

By Nicholas Bakalar Moderate alcohol consumption is associated with reduced levels of beta amyloid, the protein that forms the brain plaques of Alzheimer’s disease, a new study suggests. Korean researchers studied 414 men and women, average age 71, who were free of dementia or alcohol-related disorders. All underwent physical exams, tests of mental acuity, and PET and M.R.I. scans. They were carefully interviewed about their drinking habits. The study, in PLOS Medicine, measured drinking in “standard drinks” — 12 ounces of beer, five ounces of wine, or one-and-a-half ounces of hard liquor. Compared with abstainers, those who drank one to 13 standard drinks a week had a 66 percent lower rate of beta amyloid deposits in their brains. The results applied only to those who drank moderately for decades, and not to those who recently began drinking moderately or drank more than 13 drinks a week. The study controlled for age, sex, education, socioeconomic status, body mass index, vascular health and many other factors. Dr. Dong Young Lee, the senior author and a professor of psychiatry at Seoul National University College of Medicine, cautioned that this was an observational study that looked at people at one point in time, and does not prove cause and effect. Still, he said, “In people without dementia and without alcohol abuse or dependency, moderate drinking appears to be helpful as far as brain health is concerned.” © 2020 The New York Times Company

Keyword: Alzheimers; Drug Abuse
Link ID: 27096 - Posted: 03.06.2020

By Kelly Servick Building a beautiful robotic hand is one thing. Getting it to do your bidding is another. For all the hand-shaped prostheses designed to bend each intricate joint on cue, there’s still the problem of how to send that cue from the wearer’s brain. Now, by tapping into signals from nerves in the arm, researchers have enabled amputees to precisely control a robotic hand just by thinking about their intended finger movements. The interface, which relies on a set of tiny muscle grafts to amplify a user’s nerve signals, just passed its first test in people: It translated those signals into movements, and its accuracy stayed stable over time. “This is really quite a promising and lovely piece of work,” says Gregory Clark, a neural engineer at the University of Utah who was not involved in the research. It “opens up new opportunities for better control.” Most current robotic prostheses work by recording—from the surface of the skin—electrical signals from muscles left intact after an amputation. Some amputees can guide their artificial hand by contracting muscles remaining in the forearm that would have controlled their fingers. If those muscles are missing, people can learn to use less intuitive movements, such as flexing muscles in their upper arm. These setups can be finicky, however. The electrical signal changes when a person’s arm sweats, swells, or slips around in the socket of the prosthesis. As a result, the devices must be recalibrated over and over, and many people decide that wearing a heavy robotic arm all day just isn’t worth it, says Shriya Srinivasan, a biomedical engineer at the Massachusetts Institute of Technology. © 2020 American Association for the Advancement of Science

Keyword: Robotics
Link ID: 27095 - Posted: 03.05.2020

By David H. Freedman Two levels below ground, under a small, drab building at the University of Bonn, is a wall of cages containing mice that, according to standard tests, are extraordinarily average. They learn and remember how to run mazes no better nor worse than other mice. It takes them a typical amount of time to figure out how to extricate themselves from a tank of water with hidden exit steps. There’s nothing out of line about how they interact with other mice, nor their willingness to explore open spaces. And yet these mice are the center of attention at the lab of Andreas Zimmer. That’s because their boringly average minds may well hold the key to beating Alzheimer’s and elderly dementia. Many of the mice are 18 months old, roughly equivalent to a 70-year-old human. Mice normally start to show mental decline at around a year old, and by 18 months, struggle with mazes and other mental tasks, as well as with socializing. But not these rodent seniors. “You can’t tell the difference between them and two-month-old mice,” says Zimmer. Even more surprising is what Zimmer has done to get these elderly mice remembering and behaving like younger ones. It’s not special genes, a particular training regimen, nor an unusual diet. They don’t get any approved memory drug, nor a new investigational procedure. Basically, Zimmer keeps them very slightly stoned. A longtime U.S. National Institutes of Health (NIH) researcher who is now one of Germany’s most respected neuroscientists, Zimmer has been on a long journey to answer a question that few researchers had thought to ask: Is it possible that weed, long seen as the stuff of slackers, might actually contain the secret to sharpening the aging brain? © 2020 Kalmbach Media Co.

Keyword: Alzheimers; Drug Abuse
Link ID: 27094 - Posted: 03.05.2020

By Cindi May Music makes life better in so many ways. It elevates mood, reduces stress and eases pain. Music is heart-healthy, because it can lower blood pressure, reduce heart rate and decrease stress hormones in the blood. It also connects us with others and enhances social bonds. Music can even improve workout endurance and increase our enjoyment of challenging activities. The fact that music can make a difficult task more tolerable may be why students often choose to listen to it while doing their homework or studying for exams. But is listening to music the smart choice for students who want to optimize their learning? A new study by Manuel Gonzalez of Baruch College and John Aiello of Rutgers University suggests that for some students, listening to music is indeed a wise strategy, but for others, it is not. The effect of music on cognitive functioning appears not to be “one-size-fits-all” but to instead depend, in part, on your personality—specifically, on your need for external stimulation. People with a high requirement for such stimulation tend to get bored easily and to seek out external input. Those individuals often do worse, paradoxically, when listening to music while engaging in a mental task. People with a low need for external stimulation, on the other hand, tend to improve their mental performance with music. But other factors play a role as well. Gonzalez and Aiello took a fairly sophisticated approach to understanding the influence of music on intellectual performance, assessing not only listener personality but also manipulating the difficulty of the task and the complexity of the music. Whether students experience a perk or a penalty from music depends on the interplay of the personality of the learner, the mental task, and the music. © 2020 Scientific American

Keyword: Learning & Memory; Attention
Link ID: 27093 - Posted: 03.05.2020

By Virginia Morell Whether it’s calculating your risk of catching the new coronavirus or gauging the chance of rain on your upcoming beach vacation, you use a mix of statistical, physical, and social information to make a decision. So do New Zealand parrots known as keas, scientists report today. It’s the first time this cognitive ability has been demonstrated outside of apes, and it may have implications for understanding how intelligence evolved. “It’s a neat study,” says Karl Berg, an ornithologist and parrot expert at the University of Texas Rio Grande Valley, Brownsville, who was not involved with this research. Keas already had a reputation in New Zealand—and it wasn’t a great one. The olive-brown, crow-size birds can wield their curved beaks like knives—and did so on early settlers’ sheep, slicing through wool and muscle to reach the fat along their spines. These days, they’re notorious for slashing through backpacks for food and ripping windshield wipers off cars. To see whether keas’ intelligence extended beyond being mischievous, Amalia Bastos, a doctoral candidate in comparative psychology at the University of Auckland, and colleagues turned to six captive keas at a wildlife reserve near Christchurch, New Zealand. The researchers taught the birds that a black token always led to a tasty food pellet, whereas an orange one never did. When the scientists placed two transparent jars containing a mix of tokens next to the keas and removed a token with a closed hand, the birds were more likely to pick hands dipped into jars that contained more black than orange tokens, even if the ratio was as close as 63 to 57. That experiment combined with other tests “provide conclusive evidence” that keas are capable of “true statistical inference,” the scientists report in today’s issue of Nature Communications. © 2020 American Association for the Advancement of Science

Keyword: Evolution; Attention
Link ID: 27092 - Posted: 03.04.2020

When the spinal cord is injured, the damaged nerve fibers — called axons — are normally incapable of regrowth, leading to permanent loss of function. Considerable research has been done to find ways to promote the regeneration of axons following injury. Results of a study performed in mice and published in Cell Metabolism suggests that increasing energy supply within these injured spinal cord nerves could help promote axon regrowth and restore some motor functions. The study was a collaboration between the National Institutes of Health and the Indiana University School of Medicine in Indianapolis. “We are the first to show that spinal cord injury results in an energy crisis that is intrinsically linked to the limited ability of damaged axons to regenerate,” said Zu-Hang Sheng, Ph.D., senior principal investigator at the NIH’s National Institute of Neurological Disorders and Stroke (NINDS) and a co-senior author of the study. Like gasoline for a car engine, the cells of the body use a chemical compound called adenosine triphosphate (ATP) for fuel. Much of this ATP is made by cellular power plants called mitochondria. In spinal cord nerves, mitochondria can be found along the axons. When axons are injured, the nearby mitochondria are often damaged as well, impairing ATP production in injured nerves. “Nerve repair requires a significant amount of energy,” said Dr. Sheng. “Our hypothesis is that damage to mitochondria following injury severely limits the available ATP, and this energy crisis is what prevents the regrowth and repair of injured axons.” Adding to the problem is the fact that, in adult nerves, mitochondria are anchored in place within axons. This forces damaged mitochondria to remain in place while making it difficult to replace them, thus accelerating a local energy crisis in injured axons.

Keyword: Regeneration
Link ID: 27091 - Posted: 03.04.2020

Nicola Davis From humans to black-tailed prairie dogs, female mammals often outlive males – but for birds, the reverse is true. Now researchers say they have cracked the mystery, revealing that having two copies of the same sex chromosome is associated with having a longer lifespan, suggesting the second copy offers a protective effect. “These findings are a crucial step in uncovering the underlying mechanisms affecting longevity, which could point to pathways for extending life,” the authors write. “We can only hope that more answers are found in our lifetime.” The idea that a second copy of the same sex chromosome is protective has been around for a while, supported by the observation that in mammals – where females have two of the same sex chromosomes – males tend to have shorter lifespans. In birds, males live longer on average and have two Z chromosomes, while females have one Z and one W chromosome. Scientists say they have found the trend is widespread. Writing in the journal Biology Letters, the team report that they gathered data on sex chromosomes and lifespan across 229 animal species, from insects to fish and mammals. Hermaphroditic species and those whose sex is influenced by environmental conditions – such as green turtles – were not included. The results reveal that individuals with two of the same sex chromosomes live 17.6% longer, on average, than those with either two different sex chromosomes or just one sex chromosome. The team say the findings back a theory known as the “unguarded X hypothesis”. In human cells, sex chromosome combinations are generally either XY (male) or XX (female). In females only one X chromosome is activated at random in each cell. © 2020 Guardian News & Media Limited

Keyword: Sexual Behavior; Evolution
Link ID: 27090 - Posted: 03.04.2020

By Laura Sanders Here’s something neat about sleeping sheep: Their brains have fast zags of neural activity, similar to those found in sleeping people. Here’s something even neater: These bursts zip inside awake sheep’s brains, too. These spindles haven’t been spotted in healthy, awake people’s brains. But the sheep findings, published March 2 in eNeuro, raise that possibility. The purpose of sleep spindles, which look like jagged bursts of electrical activity on an electroencephalogram, isn’t settled. One idea is that these bursts help lock new memories into the brain during sleep. Daytime ripples, if they exist in people, might be doing something similar during periods of wakefulness, the researchers speculate. Jenny Morton, a neurobiologist at the University of Cambridge, and her colleagues studied six female merino sheep with implanted electrodes that spanned their brains. The team collected electrical patterns that emerged over two nights and a day. As the sheep slept, sleep spindles raced across their brains. These spindles are akin to those in people during non-REM sleep, which accounts for the bulk of an adult’s sleeping night (SN: 8/10/10). But the electrodes also caught spindles during the day, when the sheep were clearly awake. These “wake” spindles “looked different from those we saw at night,” Morton says, with different densities, for instance. Overall, these spindles were also less abundant and more localized, captured at single, unpredictable spots in the sheep’s brains. © Society for Science & the Public 2000–2020.

Keyword: Sleep; Evolution
Link ID: 27089 - Posted: 03.03.2020

By Simon Makin Neuroscientists understand much about how the human brain is organized into systems specialized for recognizing faces or scenes or for other specific cognitive functions. The questions that remain relate to how such capabilities arise. Are these networks—and the regions comprising them—already specialized at birth? Or do they develop these sensitivities over time? And how might structure influence the development of function? “This is an age-old philosophical question of how knowledge is organized,” says psychologist Daniel Dilks of Emory University. “And where does it come from? What are we born with, and what requires experience?” Dilks and his colleagues addressed these questions in an investigation of neural connectivity in the youngest humans studied in this context to date: 30 infants ranging from six to 57 days old (with an average age of 27 days). Their findings suggest that circuit wiring precedes, and thus may guide, regional specialization, shedding light on how knowledge systems emerge in the brain. Further work along these lines may provide insight into neurodevelopmental disorders such as autism. In the study, published Monday in Proceedings of the National Academy of Sciences USA, the researchers looked at two of the best-studied brain networks dedicated to a particular visual function—one that underlies face recognition and another that processes scenes. The occipital face area and fusiform face area selectively respond to faces and are highly connected in adults, suggesting they constitute a face-recognition network. The same description applies to the parahippocampal place area and retrosplenial complex but for scenes. All four of these areas are in the inferior temporal cortex, which is behind the ear in humans. © 2020 Scientific American,

Keyword: Development of the Brain; Vision
Link ID: 27088 - Posted: 03.03.2020

By Abdul-Kareem Ahmed “I use a spoon instead of a fork, so I spill less,” the patient said. “I eat sandwiches and hamburgers so I can use both hands to hold my food.” He was 73 and had suffered from essential tremor for the past decade. His hands would shake uncontrollably, more on the right than on the left, which would worsen if he tried using them. “I could still do crowns, but giving injections became impossible,” he said. His disease, gradual and grasping, had forced the Baltimore-area dentist into early retirement. The patient, who is not being named to protect his privacy, was going to undergo surgery to treat his tremor, which I was curious to observe. I headed to the MRI exam suite to meet him. Wearing a hospital gown, he sat at the edge of his bed, talking to the attending neurosurgeon. He was tall, and balder today than he usually was. As was required, he had shaved his head. Essential tremor is a neurological disease that can affect the torso, arms, neck, head or even voice. Medications are used to attenuate symptoms, but for many patients, these fail or are difficult to tolerate. “I don’t want to take medications forever,” he said. A particularity to this disease is social visibility. Like our patient, people with essential tremor tend to withdraw from society, feeling self-conscious about their inability to perform simple tasks. Dropping food, drinks or other objects is quickly noticed by others.

Keyword: Movement Disorders
Link ID: 27087 - Posted: 03.03.2020

By Jillian Kramer One of the strongest predictors of becoming an alcoholic is family history: the offspring of people with the disorder are four times more likely than others to develop it, according to the National Institute on Alcohol Abuse and Alcoholism (NIAAA). But new research shows a family history of alcoholism (FHA) affects more than your desire to drink. It also changes how your brain transitions from one task to the next—going, say, from cooking breakfast to thinking about a work deadline. A whole line of research has found that having an alcoholic in the family can affect one’s mental processes. But these studies have not fully explored what is called executive function—planning, restraint and other behaviors that are impaired with FHA. To delve further, Enrico Amico, now at the Swiss Federal Institute of Technology in Lausanne, and his colleagues decided to focus on how the brain processes competing cognitive demands—the switching of neural activity from one brain network to another, which is critical to executive functioning. Prior studies acquired “snapshots” of network activity when subjects were either performing a task or resting quietly. But this approach does not provide a continuous record of what is happening in the brain to capture the dynamic transitions from active to resting states that occur constantly throughout the day. So Amico, then at Purdue University, and a team of researchers at Purdue and Indiana University set out to answer how the brain makes these transitions. © 2020 Scientific American

Keyword: Drug Abuse; Genes & Behavior
Link ID: 27086 - Posted: 03.03.2020