Exercise Delays Age-Related Hearing Loss in Mice
Age-related hearing loss is a common problem in older adults, and it may be more common in those who are less physically active. In a new study, researchers find mice who run on a wheel lose fewer hair cells in the cochlea and have better hearing as they age compared to more sedentary mice. They also maintain more of the capillaries that supply the cochlea with oxygen and nutrients. The results suggest regular exercise may delay the onset of age-related hearing loss by reducing inflammation-related capillary loss in the cochlea.
Corresponding author: Shinichi Someya, someya@ufl.edu
Brain Circuit Suppresses Feeding in Mice
The drive to eat is primarily governed by circuits in the hypothalamus -- an area of the brain that regulates basic functions like hunger, thirst, temperature, and sleep -- and the brainstem. But "higher level" areas of the brain involved in cognition and emotion may also be involved. In a new study in mice, researchers find neurons in the septum -- an area of the brain involved in stress and anxiety -- suppress appetite. The results could provide new therapeutic targets for eating disorders such as anorexia.
Corresponding author: Yunlei Yang, yangyun@upstate.edu
Targeting Sleeping Drug to Specific Part of Brain Induces More Natural Sleep in Mice
Ambien is the most widely prescribed sleeping pill, and it induces sleep by helping the brain's inhibitory neurotransmitter GABA work better. But studies using electroencephalography (EEG) have found that Ambien-induced sleep produces lower-power brain waves compared to natural sleep and may be less optimal. In a new study in mice, researchers find targeting Ambien to specific parts of the brain induces sleep without reducing the power of brain waves. The results could help in the design of improved sleeping drugs.
Corresponding author: William Wisden, w.wisden@imperial.ac.uk
Synergistic Actions of Stress Hormones Impair Memory in Mice
Stress can impair memory. During a stressful experience, hormones from both the brain and other areas of the body flood the hippocampus, the area of the brain critical for learning and memory. But it's unclear if and how these molecules interact to modify memory and how long impairments may persist. In a new study in mice, researchers find that two specific hormones act synergistically to disrupt signaling in the hippocampus, producing memory deficits lasting for weeks. The results may help explain some of the memory deficits seen in people with post-traumatic stress disorder (PTSD).
Corresponding author: Tallie Z. Baram, tallie@uci.edu
The Journal of Neuroscience is published by the Society for Neuroscience, an organization of nearly 38,000 basic scientists and clinicians who study the brain and nervous system.
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Check out these newsworthy studies from the November 2, 2016, issue of JNeurosci. Media interested in obtaining the full text of the studies should contact media@sfn.org.