Topic: suprachiasmatic nuclei

Circadian rhythms are ~24-hour oscillations that provide temporal integration of physiology and behavior that are entrained to the earth’s light-dark cycle via photic input to the suprachiasmatic nuclei (SCN). The SCN (i.e., central clock), sets central and peripheral clocks accordingly to maintain proper synchronization with the external solar day. Exposure to artificial light at night (ALAN) resets the SCN, disrupting daily internal rhythms. Our lab and others have demonstrated daily rhythms in transcellular permeability via efflux mediated transport at the blood-brain barrier (BBB). However

In mammals, circadian rhythms are controlled by the central clock, suprachiasmatic nuclei (SCN) in the hypothalamus. The external light signal could entrain SCN through intrinsically photosensitive retinal ganglion cells (ipRGCs), a type of neuron in the retinal of mammalian eyes, by releasing glutamate. The innervation of ipRGCs to SCN has been revealed by using genetic tracing techniques and contributes to the synchronization of the circadian rhythm. SCN is a heterogenous structure that contains different neurons, while AVP and VIP neurons are critical for the networking of circadian rhythm.