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dopamine

Everybody knows that it’s important to stay alert behind the wheel or while out walking on the bike path. But our ability to react appropriately to sudden dangers is influenced by whether we feel momentarily tired, distracted, or anxious. How is it that the brain can transition through such different states of consciousness while performing the same routine task, even as its basic structure and internal wiring remain unchanged?

A team of NIH-funded researchers may have found an important clue in zebrafish, a popular organism for studying how the brain works. Using a powerful new method that allowed them to find and track brain circuits tied to alertness, the researchers discovered that this mental state doesn’t work like an on/off switch. Rather, alertness involves several distinct brain circuits working together to bring the brain to attention. As shown in the video above that was taken at cellular resolution, different types of neurons (green) secrete different kinds of chemical messengers across the zebrafish brain to affect the transition to alertness. The messengers shown are: serotonin (red), acetylcholine (blue-green), and dopamine and norepinephrine (yellow).

What’s also fascinating is the researchers found that many of the same neuronal cell types and brain circuits are essential to alertness in zebrafish and mice, despite the two organisms being only distantly related. That suggests these circuits are conserved through evolution as an early fight-or-flight survival behavior essential to life, and they are therefore likely to be important for controlling alertness in people too. If correct, it would tell us where to look in the brain to learn about alertness not only while doing routine stuff but possibly for understanding dysfunctional brain states, ranging from depression to post-traumatic stress disorder (PTSD).

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neuronal cell

Caption: Mouse fibroblasts converted into induced neuronal cells, showing neuronal appendages (red), nuclei (blue) and the neural protein tau (yellow).
Credit: Kristin Baldwin, Scripps Research Institute, La Jolla, CA

Writers have The Elements of Style, chemists have the periodic table, and biomedical researchers could soon have a comprehensive reference on how to make neurons in a dish. Kristin Baldwin of the Scripps Research Institute, La Jolla, CA, has received a 2016 NIH Director’s Pioneer Award to begin drafting an online resource that will provide other researchers the information they need to reprogram mature human skin cells reproducibly into a variety of neurons that closely resemble those found in the brain and nervous system.

These lab-grown neurons could be used to improve our understanding of basic human biology and to develop better models for studying Alzheimer’s disease, autism, and a wide range of other neurological conditions. Such questions have been extremely difficult to explore in mice and other animal models because they have shorter lifespans and different brain structures than humans.

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It’s not every day that an amateur guitar picker gets to play a duet with an internationally renowned classical cellist. But that was my thrill this week as I joined Yo-Yo Ma in a creative interpretation of the traditional song, “How Can I Keep from Singing?” Our short jam session capped off Mr. Ma’s appearance as this year’s J. Edward Rall Cultural Lecture.

The event, which counts The Dalai Lama, Maya Angelou, and Atul Gawande among its distinguished alumni, this year took the form of a conversation on the intersection of music and science—and earned a standing ovation from a packed house of researchers, patients, and staff here on the National Institutes of Health (NIH) campus in Bethesda, MD.

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Apple pieFor some people, the smell of Mom’s home-baked pie, the sight of an ice cream truck, or the sound of sizzling French fries can trigger a feeding frenzy. But others find it much easier to resist such temptations. What’s the explanation?

You might think it’s sheer willpower. But a recent study in the journal Molecular Psychiatry suggests the answer to what fuels susceptibility to food cues may be far more complex, related to subtle differences in brain chemistry [1].

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Photos of a healthy brain cell and a brain cell affected by Parkinson's

Caption: (LEFT) A healthy neuron with the alpha-synuclein (green) protein diffusely spread in the cell. The bright reddish dots are the garbage disposal lysosomes with alpha-synuclein entering, which gives them an orange hue. (RIGHT) This is a sick neuron from a LRRK2 brain. The lysosomes are enlarged and puffy because the alpha-synuclein is stuck outside and unable to enter the trash.
Credit: Samantha Orenstein and Dr. Esperanza Arias, Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, Bronx, New York

I’m blogging today to tell you about a new NIH funded report [1] describing a possible cause of Parkinson’s disease: a clog in the protein disposal system.

You probably already know something about Parkinson’s disease. Many of us know individuals who have been stricken, and actor Michael J. Fox, who suffers from it, has done a great job talking about and spreading awareness of it. Parkinson’s is a progressive neurodegenerative condition in which the dopamine-producing cells in the brain region called the substantia nigra begin to sicken and die. These cells are critical for controlling movement; their death causes shaking, difficulty moving, and the characteristic slow gait. Patients can have trouble swallowing, chewing, and speaking. As the disease progresses, cognitive and behavioral problems take hold—depression, personality shifts, sleep disturbances.

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