Abstract: The Drosophila circadian clock functions within 75 pairs of brain neurons. We are expanding our understanding of their organization and functions, including their contributions to behavior, their regulation of sleep and their circuitry.

New methods include calcium monitoring of discrete neuronal groups and simultaneous video recording of behavior in freely moving wake-behaving flies. This is being done over long time periods, suitable for circadian and sleep studies. The monitoring is coupled with optogenetic manipulation of individual neuronal groups.

These in vivo approaches have been combined with neuronal purification and deep sequencing “around the clock” from several of these discrete neuron groups, to identify molecules that contribute to these behaviors in a neuron-specific manner.