About Samer Hattar's Work
Understanding how light influences physiology and behavior is a fundamental biological problem, with significant relevance to human health. A critical discovery in the last decade was the identification of a new photoreceptor in the mammalian retina, the intrinsically photosensitive retinal ganglion cell. ipRGCs are pivotal for light to influence behavior. My laboratory has been at the forefront of elucidating ipRGC functions in an astonishingly broad spectrum of light-mediated behaviors, including circadian rhythms, sleep, mood, cognition and even vision. We generated innovative genetic mouse lines and through morphological and electrophysiological analyses, and quantitative behavioral assays, elucidated the remarkably diverse functions of a seemingly simple light detection system originally thought exclusive to circadian activity. Disruptions in light-dependent behaviors result in numerous health problems, including sleep disturbances, metabolic dysfunction, and depression. The basic biological insights from our studies can be readily applied to conditions such as jet lag, seasonal affective disorder and shift work.