Light effects on circadian rhythms, mood and learning

Samer Hatter


Dr. Samer Hattar; National Institute of Mental Health

February 2 at 12:20pm in the Fralin Auditorium, Fralin Hall room 102

Hosted by Dr. C. Finkielstein


Light exerts a range of powerful biological effects beyond image vision, including mood and learning regulation. While the source of photic information affecting mood and cognitive functions is well established, viz. intrinsically photosensitive retinal ganglion cells (ipRGCs), the central mediators are unknown. Here we reveal that the direct effects of light on learning and mood utilize distinct ipRGC output streams. The suprachiasmatic nucleus (SCN) is sufficient for driving ipRGC-mediated effects of light on learning, and this occurs independently of the SCN's pacemaker function. Mood regulation by light, on the other hand, requires an SCN-independent pathway linking ipRGCs to a previously unrecognized thalamic region, termed perihabenular nucleus (PHb). The PHb is integrated in a distinctive circuitry with mood-regulating centers, and is both necessary and sufficient for driving the light effects on affective behavior. Together, these results provide new insights into the neural basis required for light to influence mood and learning.

Hattar Flyer

This seminar will NOT be livestreamed or recorded.