1. Researchers develop way to stimulate formation of new neural connections in adult brain

    November 16, 2017 by Ashley

    From the University of Idaho press release:

    A team led by University of Idaho scientists has found a way to stimulate formation of new neural connections in the adult brain in a study that could eventually help humans fend off memory loss, brain trauma and other ailments in the central nervous system.

    Peter G. Fuerst, an associate professor in the College of Science’s Department of Biological Sciences and WWAMI Medical Education Program, and a team that included lead author doctoral student Aaron Simmons, were able to stimulate growth of new neural connections in mice that are needed to connect the cells into neural circuits. Their study, which included scientists from the University of Louisville and University of Puerto Rico-Humacao, is titled “DSCAM-Mediated Control of Dendritic and Axonal Arbor Outgrowth Enforces Tiling and Inhibits Synaptic Plasticity.” It was published today in the Journal Proceedings of the National Academy of Sciences.

    “The paper is a study into factors that prevent adult neurons from making new connections,” Fuerst said. “Regulation of this process is important to prevent several disorders, such as autism, but is also related to the inability of the adult nervous system to readily recover from damage.”

    Researchers studied a cell population that has the unusual ability to make new connections into adulthood, but under normal conditions does not grow the needed axons or dendrites. The team was able to genetically manipulate the cell population in the mice to induce axon and dendrite outgrowth. They found this induced the formation of stable, functional connections with new cells.

    “The idea is that one could stimulate the nervous system to make new connections if there was some kind of trauma,” Fuerst said. “Maybe this is the way to reactivate the cell to build those new connections that we can take advantage of clinically.”

    Their efforts included research through the regional WWAMI Medical Education Program at the University of Washington and could have wide ramifications for other adult neurological conditions that prevent human brains from making those needed connections as an adult.

    “In children in early development it’s very easy to make new connections, but adults lose that ability, and we want to see why that is,” he said.

    The genetic manipulation used in mice as part of the study wouldn’t work in humans. Instead, Fuerst and his team would next like to test small-molecule drugs that regulate these central nervous system processes — currently used to combat cancer in humans — to see if they can help the nervous system make new connections in mice.

    “These contributions by Peter and his team right here at the University of Idaho are helping advance global neurological research,” said Janet Nelson, vice president for research and economic development. “I’m excited by the potential impact of this research on the understanding of the brain and in advancing human health.”


  2. Engineer finds how brain encodes sounds

    by Ashley

    From the Washington University in St. Louis press release:

    When you are out in the woods and hear a cracking sound, your brain needs to process quickly whether the sound is coming from, say, a bear or a chipmunk. In new research published in PLoS Biology, a biomedical engineer at Washington University in St. Louis has a new interpretation for an old observation, debunking an established theory in the process.

    Dennis Barbour, MD, PhD, associate professor of biomedical engineering in the School of Engineering & Applied Science who studies neurophysiology, found in an animal model that auditory cortex neurons may be encoding sounds differently than previously thought. Sensory neurons, such as those in auditory cortex, on average respond relatively indiscriminately at the beginning of a new stimulus, but rapidly become much more selective. The few neurons responding for the duration of a stimulus were generally thought to encode the identity of a stimulus, while the many neurons responding at the beginning were thought to encode only its presence. This theory makes a prediction that had never been tested — that the indiscriminate, initial responses would encode stimulus identity less accurately than how the selective responses register over the sound’s duration.

    “At the beginning of a sound transition, things are diffusely encoded across the neuron population, but sound identity turns out to be more accurately encoded,” Barbour said. “As a result, you can more rapidly identify sounds and act on that information. If you get about the same amount of information for each action potential spike of neural activity, as we found, then the more spikes you can put toward a problem, the faster you can decide what to do. Neural populations spike most and encode most accurately at the beginning of stimuli.”

    Barbour’s study involved recording individual neurons. To make similar kinds of measurements of brain activity in humans, researchers must use noninvasive techniques that average many neurons together. Event-related potential (ERP) techniques record brain signals through electrodes on the scalp and reflect neural activity synchronized to the onset of a stimulus. Functional MRI (fMRI), on the other hand, reflects activity averaged over several seconds. If the brain were using fundamentally different encoding schemes for onsets versus sustained stimulus presence, these two methods might be expected to diverge in their findings. Both reveal the neural encoding of stimulus identity, however.

    “There has been a lot of debate for a very long time, but especially in the past couple of decades, about whether information representation in the brain is distributed or local,” Barbour said.

    “If function is localized, with small numbers of neurons bunched together doing similar things, that’s consistent with sparse coding, high selectivity, and low population spiking rates. But if you have distributed activity, or lots of neurons contributing all over the place, that’s consistent with dense coding, low selectivity and high population spiking rates. Depending on how the experiment is conducted, neuroscientists see both. Our evidence suggests that it might just be both, depending on which data you look at and how you analyze it.”

    Barbour said the research is the most fundamental work to build a theory for how information might be encoded for sound processing, yet it implies a novel sensory encoding principle potentially applicable to other sensory systems, such as how smells are processed and encoded.

    Earlier this year, Barbour worked with Barani Raman, associate professor of biomedical engineering, to investigate how the presence and absence of an odor or a sound is processed. While the response times between the olfactory and auditory systems are different, the neurons are responding in the same ways. The results of that research also gave strong evidence that there may exist a stored set of signal processing motifs that is potentially shared by different sensory systems and even different species.


  3. Researchers identify new protective function for a brain protein genetically linked to Alzheimer’s

    by Ashley

    From the Sanford-Burnham Prebys Medical Discovery Institute press release:

    Researchers at Sanford Burnham Prebys Medical Discovery Institute (SBP) have identified a new protective function for a brain protein genetically linked to Alzheimer’s. The findings, published in the Journal of Experimental Medicine, could inform novel treatment strategies.

    “We found that a protein called SORLA directly limits the ability of amyloid beta, the toxic protein that causes Alzheimer’s, to trigger the destruction of neuronal connections,” says Huaxi Xu, Ph.D., professor and the Jeanne and Gary Herberger Leadership Chair of SBP’s Neuroscience and Aging Research Center. (SORLA stands for sortilin-related receptor with LDLR class A repeats.) “This is actually the third way that SORLA has been shown to defend against neurodegeneration.”

    “It’s becoming increasingly clear that the SORLA gene has a major influence on Alzheimer’s development — more and more Alzheimer’s-associated mutations in the SORLA gene are being discovered,” Xu adds. “Our findings help explain why they are so important.”

    SORLA is one of many genes in which mutations are associated with increased risk of Alzheimer’s, which affects 5.5 million people in the U.S. The biggest risk factor is age — as the average life expectancy increases, the number of people with Alzheimer’s is expected to almost triple by 2050.

    Alzheimer’s begins when amyloid beta aggregates into small clusters outside neurons. Those clusters, called oligomers, induce toxic signaling that damages the connections between synapses so that neurons can no longer talk to one another. Synapse loss is the reason Alzheimer’s patients develop memory problems.

    Xu and his collaborators suspected that SORLA — a trafficking protein that shuttles molecules between cellular compartments — might help protect against amyloid beta induced toxic signaling based on their prior observations. SORLA has already been shown to counteract production of amyloid beta and eliminate it from the space around neurons.

    Xu’s team recently reported that SORLA physically interacts with EphA4, one of the receptors through which amyloid beta provokes synaptic dysfunction. (EphA4 exists primarily to control the wiring of neuronal networks as the brain develops and regulate the behavior of synapses in the adult brain.)

    In this study, Xu’s team established that SORLA could mitigate the toxic EphA4 signaling caused by amyloid beta. They also showed that increasing levels of SORLA in mice reduced cognitive impairments caused by amyloid beta.

    “These observations suggest that early-stage Alzheimer’s could be treated with drugs that increase levels of SORLA, or that enhance its interaction with EphA4,” comments Xu. “We’re currently searching for drugs that have either of these effects.

    “The researchers also found that EphA4 is over-activated in brain tissue from Alzheimer’s patients, and that over-activation correlates with decreased binding to SORLA, demonstrating the relevance of this discovery to human disease.

    “Our study also provides support to explore EphA4 inhibitors as Alzheimer’s therapeutics,” Xu notes. “There’s preclinical data from disease models suggesting they have some efficacy.”

    “SORLA is becoming a hot topic in Alzheimer’s research. No other protein has yet been found to influence Alzheimer’s pathogenesis in so many ways. And it may do even more — we plan to explore whether it modulates other cell surface amyloid beta receptors such as the cellular prion protein and the NMDA receptor.”

     


  4. How spatial navigation correlates with language

    November 15, 2017 by Ashley

    From the National Research University Higher School of Economics press release:

    Cognitive neuroscientists from the Higher School of Economics and Aarhus University experimentally demonstrate how spatial navigation impacts language comprehension. The results of the study have been published in NeuroImage.

    Language is a complicated cognitive function, which is performed not only by local brain modules, but by a distributed network of cortical generators. Physical experience such as movement and spatial motion play an important role in psychological experiences and cognitive function, which is related to how an individual mentally constructs the meaning of a sentence.

    Nikola Vukovic and Yury Shtyrov carried out an experiment at the HSE Centre for Cognition & Decision Making, which explains the relations between the systems responsible for spatial navigation and language. Using neurophysiological data, they describe brain mechanisms that support navigation systems use in both spatial and linguistic tasks.

    “When we read or hear stories about characters, we have to represent the inherently different perspectives people have on objects and events, and ‘put ourselves in their shoes’. Our study is the first to show that our brain mentally simulates sentence perspective by using non-linguistic areas typically in charge of visuo-spatial thought” says Dr. Nikola Vukovic, the scientist who was chiefly responsible for devising and running the experiment.

    Previous studies have shown that humans have certain spatial preferences that are based either on one’s body (egocentric) or are independent from it (allocentric). Although not absolute and subject to change in various situations, these preferences define how an individual perceives the surrounding space and how they plan and understand navigation in this space.

    The participants of the experiment solved two types of tasks. The first was a computer-based spatial navigation task involving movement through a twisting virtual tunnel, at the end of which they had to indicate the beginning of the tunnel. The shape of the tunnel was designed so that people with egocentric and allocentric perspectives estimated the starting point differently. This difference in their subjective estimates helped the researchers split the participants according to their reference frame predispositions.

    The second task involved understanding simple sentences and matching them with pictures. The pictures differed in terms of their perspective, and the same story could be described using first (“I”) or second person pronouns (“You”). The participants had to choose which pictures best matched the situation described by the sentence.

    During the experiment, electrical brain activity was recorded in all participants with the use of continuous electroencephalographic (EEG) data. Spectral perturbations registered by EEG demonstrated that a lot of areas responsible for navigation were active during the completion of both types of tasks. One of the most interesting facts for the researchers was that activation of areas when hearing the sentences also depended on the type of individual’s spatial preferences.

    Brain activity when solving a language task is related to a individuals’ egocentric or allocentric perspective, as well as their brain activity in the navigation task. The correlation between navigation and linguistic activities proves that these phenomena are truly connected’, emphasized Yury Shtyrov, leading research fellow at the HSE Centre for Cognition & Decision Making and professor at Aarhus University, where he directs MEG/EEG research. ‘Furthermore, in the process of language comprehension we saw activation in well-known brain navigation systems, which were previously believed to make no contribution to speech comprehension’.

    These data may one day be used by neurobiologists and health professionals. For example, in some types of aphasia, comprehension of motion-related words suffers, and knowledge on the correlation between the navigation and language systems in the brain could help in the search for mechanisms to restore these links.


  5. Neuroscientists identify source of early brain activity

    by Ashley

    From the University of Maryland press release:

    Some expectant parents play classical music for their unborn babies, hoping to boost their children’s cognitive capacity later in life. While some research supported a link between prenatal sound exposure and improved brain function, scientists had not identified any structures responsible for this link in the developing brain.

    A new study led by University of Maryland neuroscientists is the first to identify a mechanism that could explain such an early link between sound input and cognitive function, often called the “Mozart effect.” Working with an animal model, the researchers found that a type of cell present in the brain’s primary processing area during early development, long thought to form structural scaffolding with no role in transmitting sensory information, may conduct such signals after all.

    The results, which could have implications for the early diagnosis of autism and other cognitive deficits, were published in the online early edition of the Proceedings of the National Academy of Sciences on November 6, 2017.

    “Previous research documented brain activity in response to sound during early developmental phases, but it was hard to determine where in the brain these signals were coming from,” said Patrick Kanold, a professor of biology at UMD and the senior author of the research paper. “Our study is the first to measure these signals in an important cell type in the brain, providing important new insights into early sensory development in mammals.”

    Working with young ferrets, Kanold and his team directly observed sound-induced nerve impulses in subplate neurons for the first time. During development, subplate neurons are among the first neurons to form in the cerebral cortex — the outer part of the mammalian brain that controls perception, memory and, in humans, higher functions such as language and abstract reasoning. Subplate neurons help guide the formation of neural circuits, in the same way that a temporary scaffolding helps a construction crew build walls and install windows on a new building.

    Much like construction scaffolding, the role of subplate neurons is thought to be temporary. Once the brain’s permanent neural circuits form, most of the subplate neurons die off and disappear. According to Kanold, researchers assumed that subplate neurons had no role in transmitting sensory information, given their temporary structural role.

    Conventional wisdom suggested that mammalian brains transmit their first sensory signals in response to sound after the thalamus fully connects to the cerebral cortex. In many mammals used for research, the connection of the thalamus and the cortex also coincides with the opening of the ear canals, which allows sounds to activate the inner ear. This coincident timing provided further support for the traditional model of when sound processing begins in the brain.

    However, researchers had struggled to reconcile this conventional model with observations of sound-induced brain activity much earlier in the developmental process. Until his group directly measured the response of subplate neurons to sound, Kanold said, the phenomenon had largely been overlooked.

    “Our work is the first to suggest that subplate neurons do more than bridge the gap between the thalamus and the cortex, forming the structure for future circuits,” Kanold said. “They form a functional scaffolding that actually processes and transmits information before other cortical circuits are activated. It is likely that subplate neurons help determine the early functional organization of the cortex in addition to structural organization.”

    By identifying a source of early sensory nerve signals, the current study could lead to new ways to diagnose autism and other cognitive deficits that emerge early in development. Early diagnosis is an important first step toward early intervention and treatment, Kanold noted.

    “Now that we know subplate neurons are transmitting sensory input, we can begin to study their functional role in development in more detail,” Kanold said. “What is the role of sensory experience at this early stage? How might defects in subplate neurons correlate with cognitive deficits and conditions like autism? There are so many new possibilities for future research.”

    Kanold’s findings are already drawing interest from researchers who study sensory development in humans. Rhodri Cusack, a professor of cognitive neuroscience at Trinity College Dublin, in Ireland, noted that the results could have implications for the care of premature infants.

    “This paper shows that our sensory systems are shaped by the environment from a very early age,” Cusack said. “In human infants, this includes the third trimester, when many preterm infants spend time in a neonatal intensive care unit. The findings are a call to action to identify enriching environments that can optimize sensory development in this vulnerable population.”


  6. Study suggests ‘bursts’ of beta waves, not sustained rhythms, filter sensory processing in brain

    by Ashley

    From the Brown University press release:

    To better understand the brain and to develop potential therapies, neuroscientists have been investigating how “beta” frequency brainwaves help the brain filter distractions to process sensations. A new Brown University study stands to substantially refine what they thought was going on: What really matters is not a sustained elevation in beta wave power, but instead the rate of specific bursts of beta wave activity, ideally with perfect timing.

    The new insight, reported in the journal eLife, arose from the scientists looking beneath the covers of the typical practice of averaging beta brain wave data. With a closer examination, trial-by-trial for each subject, they saw that what really reflected attention and impacted perception were discrete, powerful bursts of beta waves at frequencies around 20 hertz.

    “When people were trying to block distraction in a brain area, the probability of seeing these beta events went up,” said senior author Stephanie R. Jones, an associate professor of neuroscience at Brown. “The brain seemed to be flexibly modulating the expression of these beta events for optimal perception.”

    The findings, made with consistency in humans and mice, can not only refine ongoing research into how beta waves arise and work in the brain, Jones said, but also provide guidance to clinicians as they develop therapies that seek to modulate beta waves.

    Testing touch

    The research team, led by graduate student Hyeyoung Shin, acquired the data through a series of experiments in which they measured beta waves in the somatosensory neocortex of humans and mice in the second leading up to inducing (or not inducing) varying amounts of a tactile sensation. Humans wore a cap of magnetoencephalography sensors, while mice had implanted electrodes. For people, the sensation was a tap on a finger tip or the foot. For mice, it was a wiggle of a whisker.

    Subjects were merely required to report the sensations they felt — people pushed a button, while mice were trained to lick a sensor in exchange for a reward. The researchers tracked the association of beta power with whether subjects accurately detected, or didn’t detect, stimuli. What they found, as expected, is that the more beta activity there was in the corresponding region of cortex, the less likely subjects were to report feeling a sensation. Elevated beta activity is known to help suppress distractions.

    A particularly good example, Shin said, was that in experiments where people were first instructed to focus on their foot, there was more beta power in the hand region of the neocortex. Correspondingly, more beta in the hand region resulted in less detection of a sensation in the hand.

    “We think that beta acts a filter mechanism,” Shin said.

    Beta bursts

    Consistently throughout various iterations of the experiments across both the human and mouse subjects, increases in beta activity did not manifest as a continuously elevated rhythm. Instead, when beta appeared, it quickly spiked in short, distinct bursts of power. Only if a subject’s beta was averaged over many trials would it look like a smooth plateau of high-power activity.

    After discovering this pattern, the researchers performed analyses to determine what features of the bursts best predicted whether subjects would report, or miss, a touch sensation. After all, it could be the number of bursts, their power, or maybe how long they lasted.

    What Shin and the team found is that number of bursts and their timing both mattered independently. If there were two or more bursts any time in the second before a sensation, it was significantly more likely to go undetected. Alternatively, if just one burst hit within 200 milliseconds of the sensation, the stimulus would also be more likely to be overlooked.

    “The ideal case was having large numbers and being close in timing to the stimulus,” Shin said.

    A better idea of beta

    While the study helps to characterize the nature of beta in the somatosensory neocortex, it doesn’t explain how it affects sensations, Jones acknowledged. But that’s why it is important that the results were in lockstep in both mice and in people. Confirming that mice model the human experience means researchers can rely on mice in experiments that delve more deeply into how beta bursts arise and what their consequence are in neurons and circuits. Shin is already doing experiments to dissect how distinct neural subpopulations contribute to beta bursts and somatosensory detection, respectively. Co-author and postdoctoral researcher Robert Law is applying computational neural models that link the human and animal recordings for further discovery.

    In the clinical realm, Jones said, an improved understanding of how beta works could translate directly into improving therapies such as transcranial magnetic stimulation or transcranial alternating current to treat neurological disorders, such as chronic pain, or depression. Rather than using those technologies to generate a consistent elevation in beta in a brain region, Jones said, it might be more effective to use them to induce (or suppress) shorter, more powerful bursts and to time those to be as close in time to a target brain activity as possible.

    “Typically with non-invasive brain stimulation you are trying to entrain a rhythm,” Jones said. “What our results suggest is that’s not what the brain is doing. The brain is doing this intermittent pattern of activity.”


  7. Study finds virtual reality effective in reducing pain during certain medical procedures

    by Ashley

    From the Children’s Hospital Los Angeles press release:

    Virtual reality has emerged into popular culture with an ever-widening array of applications including clinical use in a pediatric healthcare center. Children undergo necessary yet painful and distressing medical procedures every day, but very few non-pharmaceutical interventions have been found to successfully manage the pain and anxiety associated with these procedures. Investigators at Children’s Hospital Los Angeles have conducted a study to determine if virtual reality (VR) can be effectively used for pain management during blood draw. Their findings showed that VR significantly reduced patients’ and parents’ perception of acute pain, anxiety and general distress during the procedure. The results of the study are published in the Journal of Pediatric Psychology.

    “Given the immersive and engaging nature of the VR experience, this technology has the capacity to act as a preventative intervention transforming the blood draw experience into a less distressing and potentially pain-free medical procedure, particularly for patients with more anxiety about having their blood drawn,” said Jeffrey I. Gold, PhD, the director of the Pediatric Pain Management Clinic at Children’s Hospital Los Angeles.

    While previous research supported the effectiveness of distraction during painful procedures, specifically needle pain, the investigators hypothesized that the new VR technology, an arguably more powerful and immersive intervention could be even more effective at reducing pain and anxiety.

    Gold and study co-author Nicole E. Mahrer, PhD, of the Department of Anesthesiology Critical Care Medicine at CHLA, theorize that ‘VR analgesia’ or pain control originates from the neurobiological interplay of the parts of the brain that regulate the visual, auditory, and touch sensory experience to produce an analgesic effect.

    For the study, they recruited patients, ages 10 to 21 years, the patient’s caregiver and the phlebotomist in the outpatient blood draw clinic, and randomized them to receive either standard of care, which typically includes a topical anesthetic cream or spray and a movie playing in the room, or standard of care plus the virtual reality game when undergoing routine blood draw. Looking at pre-procedural and post-procedural standardized measures of pain, anxiety and satisfaction, researchers found that VR is feasible, tolerated, and well-liked by patients, their parents and the phlebotomists.

    VR, especially immersive VR, draws heavily on the limited cognitive resource of attention by drawing the user’s attention away from the hospital environment and the medical procedures and into the virtual world,” said Gold who is also a professor of Anesthesiology, Pediatrics, and Psychiatry & Behavioral Sciences at the Keck School of Medicine of USC.

    Given the significant concerns about problematic opioid use, evidence-based support for non-pharmaceutical inventions may lead to use of VR for pain management during certain medical procedures and a decreased need for narcotics.

    “Ultimately, the aim of future VR investigations should be to develop flexible VR environments to target specific acute and chronic pain conditions,” added Gold.


  8. Higher estrogen levels linked to increased alcohol sensitivity in brain’s ‘reward center’

    November 14, 2017 by Ashley

    From the University of Illinois at Chicago press release:

    The reward center of the brain is much more attuned to the pleasurable effects of alcohol when estrogen levels are elevated, an effect that may underlie the development of addiction in women, according to a study on mice at the University of Illinois at Chicago.

    Led by Amy Lasek, assistant professor of psychiatry in the UIC College of Medicine, researchers found that neurons in a region of the brain called the ventral tegmental area, or VTA (also known as the “reward center”), fired most rapidly in response to alcohol when their estrogen levels were high. This response, according to their findings published online in the journal PLOS ONE, is mediated through receptors on dopamine-emitting neurons in the VTA.

    “When estrogen levels are higher, alcohol is much more rewarding,” said Lasek, who is the corresponding author on the paper and a researcher in the UIC Center for Alcohol Research in Epigenetics. “Women may be more vulnerable to the effects of alcohol or more likely to overindulge during certain stages of their cycle when estrogen levels are higher, or may be more likely to seek out alcohol during those stages.”

    Studies indicate that gender differences in psychiatric disorders, including addiction, are influenced by estrogen, one of the primary female sex hormones. Women are more likely to exhibit greater escalation of abuse of alcohol and other drugs, and are more prone to relapse in response to stress and anxiety.

    The VTA helps evaluate whether something is valuable or good. When neurons in this area of the brain are stimulated, they release dopamine — a powerful neurotransmitter responsible for feelings of wellness — and, in large doses, euphoria. When something good is encountered — for example, chocolate — the neurons in the VTA fire more rapidly, enforcing reward circuitry that encodes the idea that chocolate is enjoyable and something to be sought out. Over time, the VTA neurons fire more quickly at the sight, or even thought of, chocolate, explained Lasek. In addiction, VTA neurons are tuned into drugs of abuse, and fire more quickly in relation to consuming or even thinking about drugs, driving the person to seek them out — often at the expense of their own health, family, friends and jobs.

    Many animal studies have shown that alcohol increases the firing of dopamine-sensitive neurons in the VTA, but little is known about exactly why this occurs.

    Lasek and her colleagues examined the relationship between estrogen, alcohol and the VTA in female mice. They used naturally cycling mice that were allowed to go through their normal estrous cycles, akin to the menstrual cycle in women.

    Mice were evaluated to determine when they entered diestrus — the phase in the estrous cycle when estrogen levels are close to their peak.

    “In mice in diestrus, estrogen levels increase to about 10 times higher than they are in estrus, the phase in which ovulation occurs and estrogen levels drop,” Lasek said.

    VTAs were taken from mice in both estrus and diestrus and kept alive in special chambers. Electrodes recorded the activity of individual dopamine-sensitive neurons in the VTA. Next, the researchers added alcohol to the chamber. Activity increased twice as much in neurons from mice in diestrus compared to the response of neurons from mice in estrus.

    Lasek and her colleagues then blocked estrogen receptors on dopamine-sensitive neurons in VTA in mice in estrus and diestrus. With the blocker present, the response to alcohol in neurons from mice in diestrus was significantly lower compared with neurons where estrogen receptors remained functional. The estrogen receptor blocker reduced the alcohol response to levels seen in mice in estrus. The responses to alcohol in neurons from mice in estrus were unaffected by the estrogen receptor blocker.

    “The increased reward response to alcohol we see when estrogen levels are high is mediated through receptors for estrogen in the VTA,” said Mark Brodie, professor of physiology and biophysics in the UIC College of Medicine and a co-author on the paper.

    Lasek believes that the increased sensitivity to alcohol in the VTA when estrogen levels peak may play a significant role in the development of addiction in women.

    “We already know that binge drinking can lead to lasting changes in the brain, and in women, those changes may be faster and more significant due to the interaction we see between alcohol, the VTA and estrogen,” Lasek said. “Binge drinking can increase the risk of developing alcoholism, so women need to be careful about how much alcohol they drink. They should be aware that they may sometimes inadvertently over-consume alcohol because the area of the brain involved in alcohol reward is responding very strongly.”


  9. Study suggests frequent alcohol drinking kills new brain cells in adults, females are more vulnerable

    November 13, 2017 by Ashley

    From the University of Texas Medical Branch at Galveston  press release:

    Researchers from The University of Texas Medical Branch at Galveston recently discovered that alcohol killed the stem cells residing in adult mouse brains. Because the brain stems cells create new nerve cells and are important to maintaining normal cognitive function, this study possibly opens a door to combating chronic alcoholism.

    The researchers also found that brain stem cells in key brain regions of adult mice respond differently to alcohol exposure, and they show for the first time that these changes are different for females and males. The findings are available in Stem Cell Reports.

    Chronic alcohol abuse can cause severe brain damage and neurodegeneration. Scientists once believed that the number of nerve cells in the adult brain was fixed early in life and the best way to treat alcohol-induced brain damage was to protect the remaining nerve cells.

    “The discovery that the adult brain produces stem cells that create new nerve cells provides a new way of approaching the problem of alcohol-related changes in the brain,” said Dr. Ping Wu, UTMB professor in the department of neuroscience and cell biology. “However, before the new approaches can be developed, we need to understand how alcohol impacts the brain stem cells at different stages in their growth, in different brain regions and in the brains of both males and females.”

    In the study, Wu and her colleagues used a cutting-edge technique that allows them to tag brain stem cells and observe how they migrate and develop into specialized nerve cells over time to study the impact of long-term alcohol consumption on them.

    Wu said that chronic alcohol drinking killed most brain stem cells and reduced the production and development of new nerve cells.

    The researchers found that the effects of repeated alcohol consumption differed across brain regions. The brain region most susceptible to the effects of alcohol was one of two brain regions where new brain cells are created in adults.

    They also noted that female mice showed more severe deficits than males. The females displayed more severe intoxication behaviors and more greatly reduced the pool of stem cells in the subventricular zone.

    Using this model, scientists expect to learn more about how alcohol interacts with brain stem cells, which will ultimately lead to a clearer understanding of how best to treat and cure alcoholism.

    Other authors include UTMB’s Erica McGrath, Junling Gao, Yong Fang Kuo, Tiffany Dunn, Moniqua Ray, Kelly Dineley, Kathryn Cunningham and Bhupendra Kaphalia.


  10. Study suggests brain activity is inherited, may inform treatment for ADHD, autism

    by Ashley

    From the Oregon Health & Science University press release:

    Every person has a distinct pattern of functional brain connectivity known as a connectotype, or brain fingerprint. A new study conducted at OHSU in Portland, Oregon, concludes that while individually unique, each connectotype demonstrates both familial and heritable relationships. The results published today in Network Neuroscience.

    “Similar to DNA, specific brain systems and connectivity patterns are passed down from adults to their children,” said the study’s principal investigator Damien Fair, Ph.D., P.A.-C., associate professor of behavioral neuroscience and psychiatry, OHSU School of Medicine. “This is significant because it may help us to better characterize aspects of altered brain activity, development or disease.”

    Using two data sets of functional MRI brain scans from more than 350 adult and child siblings during resting state, Fair and colleagues applied an innovative technique to characterize functional connectivity and machine learning to successfully identify siblings based on their connectotype.

    Through a similar process, the team also distinguished individual sibling and twin pairs from unrelated pairs in both children and adults.

    “This confirms that while unique to each individual, some aspects of the family connectome are inherited and maintained throughout development and may be useful as early biomarkers of mental or neurological conditions,” said lead author Oscar Miranda-Dominguez, Ph.D., research assistant professor of behavioral neuroscience, OHSU School of Medicine.

    Overall, the connectotype demonstrated heritability within five brain systems, the most prominent being the frontoparietal cortex, or the part of the brain that filters incoming information. The dorsal attention and default systems, important for attention or focus and internal mental thoughts or rumination, respectively, also showed significant occurrences.

    “These findings add to the way we think about normal and altered brain function,” said Fair. “Further, it creates more opportunity for personalized and targeted treatment approaches for conditions such as ADHD or autism.”