Topic: intrinsically photosensitive retinal ganglion cells

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.

In the realm of memory, environmental lighting exerts significant influence, impacting various cognitive processes such as fear and object memory. Within this context, our laboratory has previously conducted research demonstrating that brief exposure to light adversely affects social recognition memory (SRM) in mice. Specifically, we found that light exposure hampers the activity of oxytocin neurons located in the supraoptic nucleus (SON) through a pathway involving M1 SON-projecting intrinsically photosensitive retinal ganglion cells (ipRGCs) and GABAergic neurons situated in the perinuclear