Fig. 2

Melanopsin at the optic disc in ipRGC. A Melanopsin immunoreactivity is found in ipRGC (left panel) located in the membrane of soma and processes, and in all ipRGC PACAP immunoreactivity can be found primary in the cell cytoplasm and in axons (middle and left panel). Melanopsin is labelled in green, PACAP in red. B PACAP, a neurotransmitter and marker for ipRGC is widely distributed in the retina sending axons towards the optic disc (left panel). Since the optic nerve (ON) including the optic disc was cut off, there is no staining. The PACAP containing axons found in the nerve fiber layer reach the optic nerve (right panel) projecting to the brain, when optic disc was preserved. ON = optic nerve, ONL = outer nuclear layer, INL = inner nuclear layer, IPL = inner plexiform layer, GCL = ganglion cell layer. C Melanopsin immunoreactive RGC in the mouse retina (left panel) with preserved optic disc. Detection of melanopsin in a 3D reconstruction of the mouse papilla showing melanopsin immunoreactivity in green. The overview shows with indication of the papilla (dashed line) surrounded by melanopsin nerve fibers and cell bodies. In the right panel: Melanopsin immunoreactive RGC in the optic disc of the mouse retina. At higher magnification (than the left panel) the papilla is shown in which melanopsin nerve fibers are observed to be leaving the eye. The dashed line indicates the optic disc margin. Melanopsin immunoreactivity in green shows abundant axons within the optic disc as well as some cell bodies with melanopsin at the edge of the optic disc