CHARACTERIZATION AND DEVELOPMENT OF THE M2 MELANOPSIN RETINAL GANGLION CELL IN THE CLM-1 TRANSGENIC MOUSE RETINA

Abstract

Retinal ganglion cells (RGCs) undergo continued maturation after birth. RGC development can be influenced by light, but for most RGCs this requires the development of functional retinal circuits that occurs up to 2 weeks after birth. A subpopulation of RGCs express melanopsin (MRGCs) making them intrinsically photosensitive at birth. I hypothesized that this intrinsic photosensitivity could affect the morphology of MRGCs during the postnatal (PN) developmental period (PN 3 to adult). I took advantage of the Clomeleon-expressing transgenic mouse line that, combined with melanopsin immunohistochemistry, allowed for the systematic identification of the M2 MRGC at different PN periods. The pattern of development of the M2 MRGC, characterized through the analysis of 6 morphological parameters, was similar to that described for other types of RGCs. Thus, despite being intrinsically photosensitive, M2 MRGCs did not show substantial developmental differences from other RGC types