_{Circadian and Circatidal Rhythms} 

Our environment is constantly changing.  The Sun rises and sets every day, causing rhythmic changes in light and temperature.  At most latitudes, weather and day length vary as seasons pass.  On the coastline, tides rise and fall.  Because these environmental cycles occur with precise periodicities, most organisms on Earth have acquired biological clocks that can track and predict them.  Organisms can thus adapt and anticipate changes in light intensity, temperature, day length or water level by adjusting their physiology and behavior in a time-dependent manner.  

Circadian clocks have a period of 24 hours and synchronize to daily environmental cycles.  They regulate complex behaviors such as the sleep/wake cycle, as well as metabolism and physiology throughout our body. Their disruption - for instance due to shift work - can have serious detrimental health consequences. Circatidal clocks are found in coastal organisms.  They have a period of 12.4 hours and synchronize to tides. Our lab’s overall objective is to elucidate basic molecular and neural mechanisms that underlie circadian and circatidal rhythms, and to understand how biological clocks allow for behavioral adaptations to environmental cycles.  Most of our work is performed in Drosophila melanogaster, a fantastic model organism to study the fundamental mechanisms underlying circadian rhythms and one of its critical outputs: sleep.  We have also recently started to use Parhyale hawaiensis, a genetically-tractable crustacean, to study circatidal clocks, the mechanisms of which are very poorly understood.

For more information, please visit our lab page at:  https://www.umassmed.edu/emerylab/