News by Subject Medicine & Health

Researchers from the University of Tsukuba have discovered a group of neurons in the mouse brainstem that control muscle tone. Inhibiting these neuronal cells caused mice to move during REM sleep, reminiscent of REM sleep behavior disorders. These neurons were also responsible for episodes of cataplexy in a mouse model of narcolepsy; inhibiting them reduced the number of cataplexic bouts. These circuits could thus be a new target for treating these sleep disorders.

An exhaustive dataset drawn from mammalian macrophage cells establishes that macrophage activity is controlled by circadian timing, and - with a substantial mismatch between oscillating proteins and mRNA - hints at unexpected calibration of that timing.

In work that could help unravel the origin of sleep, an international team of researchers led by Kyushu University has shown that tiny, water-dwelling hydras not only show signs of a sleep-like state despite lacking central nervous systems but also respond to molecules associated with sleep in more evolved animals. The new results suggest that many sleep-related mechanisms developed before the brain and may have been conserved during the evolution of central nervous systems.

What happens in the brain when our conscious awareness fades during general anesthesia and normal sleep? Finnish scientists studied this question with novel experimental designs and func-tional brain imaging. They succeeded in separating the specific changes related to consciousness from the more widespread overall effects, and discovered that the effects of anesthesia and sleep on brain activity were surprisingly similar. These novel findings point to a common central core brain network fundamental for human consciousness.

The loss and return of consciousness is linked to the same network of brain regions for both sleep and anesthesia, according to new research published in JNeurosci.

In an article in Cell, National Institutes of Health-funded researchers described how they used advanced genetic engineering techniques to transform a bacterial protein into a new research tool that may help monitor serotonin transmission with greater fidelity than current methods. Preclinical experiments, primarily in mice, showed that the sensor could detect subtle, real-time changes in brain serotonin levels during sleep, fear, and social interactions, as well as test the effectiveness of new psychoactive drugs.