Light effects on circadian rhythm collected by rod cells and cone cells and the retinal ganglion cells (RGCs), or it is directly collected by these RGCs. The RGCs use the photopigment melanopsin to absorb the light energy. Specifically, this class of RGCs being discussed is referred to as "intrinsically photosensitive," which just means they are sensitive to light. There are five known types of intrinsically photosensitive retinal ganglion cells (ipRGCs): M1, M2, M3, M4, and M5. Each of these differently ipRGC types have different melanopsin content and photosensitivity. These connect to amacrine cells in the inner plexiform layer of the retina. Ultimately, via this retinohypothalamic
AII amacrine cells small proportion of rods contact the cone bipolar cells directly." AII amacrine cells AII amacrine cells are a subtype of amacrine cells present in the retina of mammals. AII amacrine cell serve the critical role of transferring light signals from rod photoreceptors to the retinal ganglion cells (which contain the axons of the optic nerve) The Classical Rod Pathway described the role of AII amacrine cells in the mammalian retina. This can be summarised as follows: (Once activated, the AII amacrine cell then modulates the cone ON and OFF channels): The ON- and OFF- cone bipolar cells in turn contact