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The Veins in Your Brain Don’t All Act the Same
Certain blood vessels in the brainstem constrict when blood vessels elsewhere in the body would dilate. And that contrary behavior is what keeps us breathing, according to a new paper by UConn researchers published May 8 in the journal eLife.

If the body were a marching band, the brainstem would be the drum major. It keeps our heart beating and our lungs breathing in the essential rhythms of life. And just like a drum major, the job is more complex than it looks. If cellular waste products build up in the body, the brainstem has to jolt the lungs into action without disrupting other bodily functions, as surely as a drum major reins in a wayward woodwind section without losing the low brass.

Neuroscientists studying the brainstem have focused on neurons, which are brain cells that send signals to one another and all over the body. But focusing just on the neurons in the brainstem is like staring only at the drum major’s hands. Recently, neuroscientists have come to understand that astrocytes, cells once thought to simply provide structure to the brain, also release signaling molecules that regulate neurons’ function. But until now, no one even considered the possibility that blood vessels may be similarly specialized.

For more than a century, doctors and scientists have known that blood vessels dilate when cellular waste products like carbon dioxide build up. Widening the vessels allows fresh blood to flush through, carrying in oxygen and washing away the acidic carbon dioxide. This has been shown to be true throughout the body, and is standard dogma in undergraduate physiology classes.

UConn physiologist Dan Mulkey was teaching exactly that to undergraduates one day when he realized that it couldn’t possibly be true in a certain part of the brainstem.

“I thought, wow. If that happened in the region of the brain I study, it would be counterproductive,” Mulkey says. He studies the retrotrapezoid nucleus (RTN), a small region in the brainstem that controls breathing. He’s shown in the past that RTN neurons respond to rising levels of carbon dioxide in the bloodstream by stimulating the lungs to breathe. But if the blood vessels in the RTN dilated in response to rising carbon dioxide the same way blood vessels do everywhere else, it would wash out that all-important signal, preventing cells in the RTN from doing their job driving us to breathe. It would be as if the drum major didn’t notice the percussion section wandering off to left field.

When Mulkey returned to the lab, he asked his team, including NIH postdoctoral fellow Virginia Hawkins, to see how blood vessels in thin slices of brainstem respond to carbon dioxide. And they saw it was indeed true – RTN blood vessels constricted when carbon dioxide levels rose. But blood vessels from slices of cortex (the wrinkled top part of the brain) dilated in response to high carbon dioxide, just like the rest of the body.

But how did the blood vessels know to act differently in the RTN? Mulkey guessed that RTN astrocytes had something to do with it. He suspected that the astrocytes were releasing adenosine triphosphate (ATP), a small molecule cells can use to signal one another. And that was causing the RTN blood vessels to constrict.

When they tested it, they found the hypothesis was correct. The astrocytes in the RTN were behaving differently than astrocytes anywhere else in the body. When these brainstem astrocytes detected high levels of carbon dioxide, they released ATP signaling to the neurons and blood vessels.

Source & further reading:
http://today.uconn.edu/2017/05/veins-brain-dont-act/

Paper:
https://elifesciences.org/articles/25232

Photo:
A blood vessel in the retrotrapezoid nucleus (RTN). Endothelial cells lining the vessel are purple, red blood cells are red, and neurons are green. Astrocytes are not identified in this image, but would be among the greyed background cells.
Credit: Dan Mulkey/UConn

#astrocytes #brainstem #bloodvessels #retrotrapezoidnucleus #breathing #neuroscience

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You’re Not Too Old to Learn That
One day, our brains will not work the way they used to, we won’t be as “sharp” as we once were, we won’t be able to remember things as easily.

This is what’s been engrained in us. We’re even led to believe that we can’t learn new skills, or take in certain information such as language, past a certain age.

But, a new theory holds that it doesn’t have to be that way. In fact, as adults, if we continue to learn the way we did as children, UCR psychology professor Rachel Wu asserts, we can redefine what it means to be an “aging” adult.

Wu has published “A Novel Theoretical Life Course Framework for Triggering Cognitive Development Across the Lifespan,” in the journal Human Development. In the paper, she redefines healthy cognitive aging as a result of learning strategies and habits that are developed throughout our life. These habits can either encourage or discourage cognitive development.

“We argue that across your lifespan, you go from ‘broad learning’ (learning many skills as an infant or child) to ‘specialized learning,’ (becoming an expert in a specific area) when you begin working, and that leads to cognitive decline initially in some unfamiliar situations, and eventually in both familiar and unfamiliar situations,” Wu said.

Read the paper:
https://www.karger.com/Article/Abstract/458720

Source:
https://ucrtoday.ucr.edu/45473

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Wu took up painting seven years ago. At first, she was told she was terrible (painting on left). But, after years of practicing and taking courses, she was told she was talented (painting on the right).

#neuroscience #cognitivefunction #aging #learning
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Parkinson’s disease in a dish: Researchers reproduce brain oscillations that characterize the disease
Abnormal oscillations in neurons that control movement, which likely cause the tremors that characterize Parkinson’s disease, have long been reported in patients with the disease. Now, University at Buffalo researchers working with stem cells report that they have reproduced these oscillations in a petri dish, paving the way for much faster ways to screen for new treatments or even a cure for Parkinson’s disease.

The paper is published online in Cell Reports.

“With this new finding, we can now generate in a dish the neuronal misfiring that is similar to what occurs in the brain of a Parkinson’s patient,” said Jian Feng, PhD, senior author on the paper and professor in the Department of Physiology and Biophysics in the Jacobs School of Medicine and Biomedical Sciences at UB. “A variety of studies and drug discovery efforts can be implemented on these human neurons to speed up the discovery of a cure for Parkinson’s disease.”

The work provides a useful platform for better understanding the molecular mechanisms at work in the disease, he added.

Source & further reading:
http://www.buffalo.edu/news/releases/2017/05/002.html

Journal article:
https://www.ncbi.nlm.nih.gov/pubmed/28467897

Image via UCSB (University of California Santa Barbara)

#parkinson'sdisease #dopamine #oscillations #dopaminergicneurons #neuroscience

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Researchers create human inner ear organs that could lead to new therapies for hearing, balance impairments
Researchers at Indiana University School of Medicine have successfully developed a method to grow inner ear tissue from human stem cells—a finding that could lead to new platforms to model disease and new therapies for the treatment of hearing and balance disorders.

“The inner ear is only one of few organs with which biopsy is not performed and because of this, human inner ear tissues are scarce for research purposes,” said Eri Hashino, PhD, Ruth C. Holton Professor of Otolaryngology at IU School of Medicine. “Dish-grown human inner ear tissues offer unprecedented opportunities to develop and test new therapies for various inner ear disorders.”

The study, published online May 1, 2017, in Nature Biotechnology, was led by Karl R. Koehler, PhD, assistant professor in the Department of Otolaryngology and Head and Neck Surgery at IU School of Medicine, and Dr. Hashino in collaboration with Jeffrey Holt, PhD, professor of otology and laryngology at Harvard Medical School and Boston Children’s Hospital.

The research builds on the team’s previous work with a technique called three-dimensional culture, which involves incubating stem cells in a floating ball-shaped aggregate, unlike traditional cell culture in which cells grow in a flat layer on the surface of a culture dish. This allows for more complex interactions between cells, and creates an environment that is closer to what occurs in the body during development, Dr. Koehler said.

By culturing human stem cells in this manner and treating them with specific signaling molecules, the investigators were able to guide cells through key processes involved in the development of the human inner ear. This resulted in what the scientists have termed inner ear “organoids,” or three-dimensional structures containing sensory cells and supporting cells found in the inner ear.

“This is essentially a recipe for how to make human inner ears from stem cells,” said Dr. Koehler, lead author of the study and whose research lab works on modeling human development. “After tweaking our recipe for about a year, we were shocked to discover that we could make multiple inner ear organoids in each pea-sized cell aggregate.”

The researchers used CRISPR gene editing technology to engineer stem cells that produced fluorescently labeled inner ear sensory cells. Targeting the labeled cells for analysis, they revealed that their organoids contained a population of sensory cells that have the same functional signature as cells that detect gravity and motion in the human inner ear.

“We also found neurons, like those that transmit signals from the ear to the brain, forming connections with sensory cells,” Dr. Koehler said. “This is an exciting feature of these organoids because both cell types are critcal for proper hearing and balance.”

Dr. Hashino said these findings are “a real game changer, because up until now, potential drugs or therapies have been tested on animal cells, which often behave differently from human cells.”

The researchers are currently using the human inner ear organoids to study how genes known to cause deafness interrupt normal development of the inner ear and plan to start the first-ever drug screening using human inner ear organoids.

Source:
http://news.medicine.iu.edu/releases/2017/05/iu-researchers-inner-ear.shtml

Journal article:
https://www.ncbi.nlm.nih.gov/pubmed/28459451

Image: Human inner ear organoid with sensory hair cells (cyan) and sensory neurons (yellow). An antibody for the protein CTBP2 reveals cell nuclei as well as synapses between hair cells and neurons (magenta).
Credit: KARL KOEHLER

#stemcells #innerear #earorganoids #neurons #hearing #neuroscience #science
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Estrogen Alters Memory Circuit Function in Women with Gene Variant
Fluctuations in estrogen can trigger atypical functioning in a key brain memory circuit in women with a common version of a gene, NIMH scientists have discovered. Brain scans revealed altered circuit activity linked to changes in the sex hormone in women with the gene variant while they performed a working memory task.

The findings may help to explain individual differences in menstrual cycle and reproductive-related mental disorders linked to fluctuations in the hormone. They may also shed light on mechanisms underlying sex-related differences in onset, severity, and course of mood and anxiety disorders and schizophrenia. The gene-by-hormone interaction’s effect on circuit function was found only with one of two versions of the gene that occurs in about a fourth of white women.

Drs. Karen Berman, Peter Schmidt, Shau-Ming Wei, and colleagues, of the NIMH Intramural Research Program, report on this first such demonstration in women April 18, 2017 in the journal Molecular Psychiatry.

Prior to the study, there was little evidence from research on the human brain that might account for individual differences in cognitive and behavioral effects of sex hormones. For example, why do some women develop postpartum depression and others do not – in response to the same hormone changes? Why do some women report that estrogen replacement improved their memory, whereas large studies of postmenopausal estrogen therapy show no overall improvement in memory performance?

Evidence from humans has also been lacking for the neural basis of stark sex differences in prevalence and course of mental disorders that are likely related to sex hormones. For example, why are there higher rates of mood disorders in females and higher rates of ADHD in males – or later onset of schizophrenia in females?

In seeking answers to these questions, the researchers focused on working memory, a well-researched brain function often disturbed in many of these disorders. It was known that working memory is mediated by a circuit from the brain’s executive hub, the prefrontal cortex, to its memory hub, the hippocampus. Notably, hippocampus activity is typically suppressed during working memory processing.

Following-up on a clue from experiments in mice, the NIMH team hypothesized that estrogen tweaks circuit function by interacting with a uniquely human version of the gene that codes for brain derived neurotrophic factor (BDNF), a pivotal chemical messenger operating in this circuit. To find out, the researchers experimentally manipulated estrogen levels in healthy women with one or the other version of the BDNF gene over a period of months. Researchers periodically scanned the women’s brain activity while they performed a working memory task to see any effects of the gene-hormone interaction on circuit function.

The researchers first scanned 39 women using PET (positron emission tomography) and later confirmed the results in 27 women using fMRI (functional magnetic resonance imaging). Both pegged atypical activity in the hippocampus to the interaction. Turning up the same findings using two types of neuroimaging strengthens the case for the accuracy of their observations, say the researchers. Such gene-hormone interactions affecting thinking and behavior are consistent with findings from animal studies and are suspect mechanisms conferring risk for mental illness, they add.

Source & further reading:
https://www.nimh.nih.gov/news/science-news/2017/estrogen-alters-memory-circuit-function-in-women-with-gene-variant.shtml

Journal article:
http://www.nature.com/mp/journal/vaop/ncurrent/full/mp201772a.html?foxtrotcallback=true

Image:
Both PET scans (left) and fMRI scans (right) showed the same atypical activation (yellow) in the brain’s memory hub, or hippocampus, in response to estrogen in women performing a working memory task – if they carried a uniquely human version of the BDNF gene. Activity in this area is typically suppressed during working memory. Picture shows PET and fMRI data superimposed over anatomical MRI image.

#estrogen #braincircuitry #neuroimaging #brainderivedneurotrophicfactor #genevariants #hippocampus #neuroscience
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When love hurts, a placebo can help
Feeling heartbroken from a recent breakup? Just believing you’re doing something to help yourself get over your ex can influence brain regions associated with emotional regulation and lessen the perception of pain.

That’s the takeaway from a new CU Boulder study that measured the neurological and behavioral impacts the placebo effect had on a group of recently broken-hearted volunteers.

“Breaking up with a partner is one of the most emotionally negative experiences a person can have, and it can be an important trigger for developing psychological problems,” said first author and postdoctoral research associate Leonie Koban, noting that such social pain is associated with a 20-fold higher risk of developing depression in the coming year. “In our study, we found a placebo can have quite strong effects on reducing the intensity of social pain.”

For decades, research has shown that placebos – sham treatments with no active ingredients – can measurably ease pain, Parkinson’s disease and other physical ailments.

The new study, published in March in the Journal of Neuroscience, is the first to measure placebos’ impact on emotional pain from romantic rejection.

Source & further reading:
http://www.colorado.edu/today/2017/04/24/when-love-hurts-placebo-can-help

Journal article:
http://www.jneurosci.org/content/early/2017/03/06/JNEUROSCI.2658-16.2017

#neuroscience #love #placebo #emotionalpain
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Cell biologists discover crucial ‘traffic regulator’ in neurons
Cell biologists led by Utrecht University’s Professor Casper Hoogenraad have discovered the protein that may be the crucial traffic regulator for the transport of vital molecules inside nerve cells. When this traffic regulator is removed, the flow of traffic comes to a halt.

The resulting ‘traffic jams’ are reported to play a key role in neurodegenerative diseases such as Alzheimer and Parkinson’s disease. The discovery of this traffic regulator may therefore be crucial for a better understanding of the development of neural disorders. The results of their research were published in the scientific journal Neuron on Wednesday 19 April.

Source & further reading:
https://www.uu.nl/en/news/cell-biologists-discover-crucial-traffic-regulator-in-neurons

Journal article:
http://www.cell.com/neuron/fulltext/S0896-6273(17)30290-8

#neuroscience #sensoryneurons #MAP2 #nervecells #neurodegenerativediseases #axonaltransport

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Infographic: The Brain on Psychedelics
Key brain areas involved in the effects of psychedelic drugs are located in the default mode network (DMN), which is more active at rest than when attention is focused on the external environment. Neuroscientists first discovered this network while scanning participants’ brains at rest: rather than a decrease in activity across the brain, they found that activity in some regions was actually higher when people were not engaged in a goal-directed task. Over the years, researchers have linked the DMN to a variety of functions, including autobiographical recollection, mind wandering, and processing self-related information.

Key hubs of the DMN include the posterior cingulate cortex (PCC), the medial prefrontal cortex (mPFC), and the posterior inferior parietal lobule (pIPL). Through neuroimaging, researchers have discovered that psychedelic drug use decreases activity in some of these brain areas, and also reduces connectivity within the DMN.

Neuroimaging studies have also shown that connectivity between brain networks is increased when psychedelics are administered. For example, the DMN; the salience network, which helps identify behaviorally relevant information; and the frontoparietal network, known to be involved in attentional control and conscious awareness, all show stronger connections to each other. Researchers believe that this increased crosstalk throughout the brain may play a key role in the drugs’ effects.

Psychedelics’ Anti-inflammatory Effects

Scientists have discovered that a number of psychedelics can reduce inflammation throughout the body. Animal studies with one of these drugs, DOI, which is an especially potent anti-inflammatory compound, are starting to reveal the mechanism behind these effects. According to one hypothesis, DOI binds to and activates the serotonin 2A (5-HT2A) receptor to recruit protein kinase C (PKC). This is thought to block the downstream effects of the binding of tumor necrosis factor-alpha (TNF-α) to its receptor (TNFR), which is known to initiate a signaling cascade that promotes the transcription of proinflammatory genes.

Full story via The Scientist
http://www.the-scientist.com/?articles.view/articleNo/50209/title/Decoding-the-Tripping-Brain/

#infographic by CATHERINE DELPHIA

#neuroscience #brain #psychedelics #research

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Music Has Powerful (and Visible) Effects on the Brain
It doesn’t matter if it’s Bach, the Beatles, Brad Paisley or Bruno Mars. Your favorite music likely triggers a similar type of activity in your brain as other people’s favorites do in theirs.

That’s one of the things Jonathan Burdette, M.D., has found in researching music’s effects on the brain.

“Music is primal. It affects all of us, but in very personal, unique ways,” said Burdette, a neuroradiologist at Wake Forest Baptist Medical Center. “Your interaction with music is different than mine, but it’s still powerful.

“Your brain has a reaction when you like or don’t like something, including music. We’ve been able to take some baby steps into seeing that, and ‘dislike’ looks different than ‘like’ and much different than ‘favorite.’”

To study how music preferences might affect functional brain connectivity – the interactions among separate areas of the brain – Burdette and his fellow investigators used functional magnetic resonance imaging (fMRI), which depicts brain activity by detecting changes in blood flow. Scans were made of 21 people while they listened to music they said they most liked and disliked from among five genres (classical, country, rap, rock and Chinese opera) and to a song or piece of music they had previously named as their personal favorite.

Those fMRI scans showed a consistent pattern: The listeners’ preferences, not the type of music they were listening to, had the greatest impact on brain connectivity – especially on a brain circuit known to be involved in internally focused thought, empathy and self-awareness. This circuit, called the default mode network, was poorly connected when the participants were listening to the music they disliked, better connected when listening to the music they liked and the most connected when listening to their favorites.

The researchers also found that listening to favorite songs altered the connectivity between auditory brain areas and a region responsible for memory and social emotion consolidation.

Source & further reading:
http://www.newswise.com/articles/music-has-powerful-and-visible-effects-on-the-brain

#neuroscience #music #functionalconnectivity #brainactivity #neuroimaging
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Could ‘love hormone’ help drug addicts stay clean?
Experts say oxytocin, a key hormone made naturally by the brain, could hold the key to treating drug addicts and help them avoid relapse.

Oxytocin is most usually associated with childbirth and breast feeding, but has multiple psychological effects, influencing social behavior and emotion.

Sometimes called the ‘love hormone’, it has an anti-anxiety effect, and many studies have examined the role of oxytocin in addiction.

Researchers at St George’s, University of London, after reviewing all the published evidence on oxytocin, have now found that the oxytocin system is profoundly affected by opioid use and abstinence.

The review suggests the oxytocin system can be an important target for developing new medicines for the treatment of opioid addiction and prevention of relapse among addicts.

Taking drugs activates pathways in the brain that induce pleasurable effects, which make the user want to repeat the experience, but as drug use continues, brain tolerance to the effects of the drug increases and a greater dose is needed to achieve the same effects.

Dr Alexis Bailey, senior author of the review, said: “Given the benefits that social support programs like Alcoholics Anonymous and Narcotics Anonymous have in keeping addicts abstinent, our findings in the review suggest the use of oxytocin, the pro-social hormone, could be an effective therapy for the prevention of relapse to drug use in drug-dependent individuals.

“Since the evidence is so clear, the need for more clinical studies looking into this is obvious.” The review is published in the British Journal of Pharmacology.

Source:
https://www.sgul.ac.uk/news/news-archive/could-love-hormone-help-drug-addicts-stay-clean

Journal article:
http://onlinelibrary.wiley.com/doi/10.1111/bph.13757/pdf

#neuroscience #oxytocin #drugaddiction #opioiddrugs #amygdala
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