In humans and other animals, signals from a central circadian clock in the brain generate the seasonal and daily rhythms of life. They help the body to prepare for expected changes in the environment and also optimize when to sleep, eat and do other daily activities. Scientists at Washington University in St.
Louis are working out the particulars of how our internal biological clocks keep time. Their new research, published July 24 in the Proceedings of the National Academy of Sciences , helps answer longstanding questions about how circadian rhythms are generated and maintained. In all mammals, the signals for circadian rhythms come from a small part of the brain called the suprachiasmatic nucleus, or SCN.
Several previous studies from WashU and other institutions have attempted to determine if a neurotransmitter called GABA plays a role in synchronizing circadian rhythms among individual SCN neurons. However, the role of GABA in the SCN had remained unclear. In the past, we have published data on pharmacological blocking of the GABA system and found only modest increases in synchrony among SCN cells.
" Daniel Granados-Fuentes, research scientist in Arts & Sciences and first author of the new study The chemical interventions that he and other scientists introduced didn't seem to change the way that neurons in the SCN fired that much, or to affect circadian regulation of actual behavior in mice, either. So Granados-Fuentes and his team members took a different approach. The re.