Melanopsin-expressing retinal ganglion cells are intrinsically photosensitive cells that are involved in non-image forming visual processes such as the pupillary light reflex and circadian entrainment but also contribute to visual perception. Here we used immunohistochemistry to study the morphology, density, distribution, and synaptic connectivity of melanopsin-expressing ganglion cells in four post mortem human donor retinas. Two types of melanopsin-expressing ganglion cells were distinguished based on their dendritic stratification near either the outer or the inner border of the inner plexiform layer. Outer stratifying cells make up on average 60% of the melanopsin-expressing cells. About half of the melanopsin-expressing cells (or 80% of the outer stratifying cells) have their soma displaced to the inner nuclear layer. Inner stratifying cells have their soma exclusively in the ganglion cell layer and include a small proportion of bistratified cells. The dendritic field diameter of melanopsin-expressing cells ranges from 250 (near the fovea) to 1,000 µm in peripheral retina. The dendritic trees of outer stratifying cells cover the retina independent of soma location. The dendritic fields of both outer and inner stratifying cells show a high degree of overlap with a coverage factor of approximately two. Melanopsin-expressing cells occur at an average peak density of between ∼20 and ∼40 cells/mm2 at about 2 mm eccentricity, the density drops to below ∼10 cells/mm2 at about 8 mm eccentricity. Both the outer and inner stratifying dendrites express postsynaptic density (PSD95) immunoreactive puncta suggesting that they receive synaptic input from bipolar cells.
Pubmed ID: 28097654 RIS Download
Publication data is provided by the National Library of Medicine ® and PubMed ®. Data is retrieved from PubMed ® on a weekly schedule. For terms and conditions see the National Library of Medicine Terms and Conditions.
This monoclonal targets PSD95 clone K28/43
View all literature mentionsThis polyclonal targets Choline Acetyltransferase
View all literature mentionsThis monoclonal targets PSD95 clone K28/43
View all literature mentionsThis polyclonal targets Choline Acetyltransferase
View all literature mentions