1. Designing life.
A California company says it can decipher almost all the DNA code of a days-old embryo created through in vitro fertilization (IVF)—a challenging feat because of the tiny volume of genetic material available for analysis. The advance depends on fully sequencing both parents’ DNA and “reconstructing” an embryo’s genome with the help of those data. And the company suggests it could make it possible to forecast risk for common diseases that develop decades down the line. Currently, such genetic risk prediction is being tested in adults, and sometimes offered clinically. The idea of applying it to IVF embryos has generated intense scientific and ethical controversy. But that hasn’t stopped the technology from galloping ahead. (Source: science.org)
2. Dopamine as neuromodulator.
Every time you reach for your coffee mug, a neuroscientific mystery takes shape. Moments before you voluntarily extend your arm, thousands of neurons in the motor regions of your brain erupt in a pattern of electrical activity that travels to the spinal cord and then to the muscles that power the reach. But just prior to this massively synchronized activity, the motor regions in your brain are relatively quiet. For self-driven movements like reaching for your coffee, the “go” signal that tells the neurons precisely when to act — instead of the moment just before or after — has yet to be found.
In a recent paper in eLife, a group of neuroscientists led by John Assad at Harvard Medical School finally reveals a key piece of the signal. It comes in the form of the brain chemical known as dopamine, whose slow ramping up in a region lodged deep below the cortex closely predicted the moment that mice would begin a movement — seconds into the future.
The new paper is one of the latest results to expand our knowledge of the crucial and varied roles that neuromodulators play in the brain. With recent advances in technology, neuroscientists can now view neuromodulators at work in networks that traverse the entire brain. The new findings are overturning some long-held views about these modulators adrift in the brain, and they’re revealing exactly how these molecules allow the brain to flexibly change its internal state amid ever-changing environments. (Source: quantamagazine.org)
3. A voice, at last.
A completely paralyzed man has been able to communicate entire sentences using a device that records his brain activity. The man was able to train his mind to use the device, which was implanted in his brain, to ask for massages, soup, and beer, and to watch films with his son.
It is the first time a completely locked-in person—someone who is conscious and cognitively able but completely paralyzed— has been able to communicate in this way, say the researchers behind the work. (Source: technologyreview.com)
4. Niacin and Alzheimer’s disease.
Indiana University School of Medicine researchers found that niacin limits Alzheimer's disease progression when used in models in the lab, a discovery that could potentially pave the way toward therapeutic approaches to the disease.
The study, recently published in Science Translational Medicine, investigates how niacin modulates microglia response to amyloid plaques in an Alzheimer's disease animal model.
In the brain, niacin interacts with a highly-selective receptor, HCAR2, present in immune cells physically associated with amyloid plaques. When niacin-;used in this project as the FDA-approved Niaspan drug-;activates the receptor, it stimulates beneficial actions from these immune cells, Landreth said.
"After the Alzheimer's disease animal models received niacin, they ended up with fewer plaques and they have improved cognition," Landreth said, "and we directly showed that these actions were due to the HCAR2 receptor." (Sources: news-medical.net, science.org)
5. Birth control:
A team of scientists yesterday said they had developed a male oral contraceptive that was 99 percent effective in mice and didn't cause observable side effects, with the drug expected to enter human trials by the end of this year.
The findings will be presented at the American Chemical Society's spring meeting, and mark a key step towards expanding birth control options – as well as responsibilities – for men. (Source: afp.com, sciencealert.com, acs.org)
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