Purchase this article with an account.
Ulrike Grunert, Subha Nasir Ahmad, Sammy Chi Sam Lee, Paul R Martin; Melanopsin-expressing ganglion cells in human retina. Invest. Ophthalmol. Vis. Sci. 2017;58(8):4136.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Melanopsin-expressing cells are spared from ganglion cell loss in some retinal diseases, yet are more vulnerable in other diseases. The present study aimed to extend the knowledge about density and spatial distribution of melanopsin containing ganglion cells across normal human retina.
Five post mortem human donor eyes, from one female and four males aged 44, 48, 53, 59, and 64 years, were obtained from the Lions NSW Eye Bank at Sydney Hospital and Sydney Eye Hospital with ethical approval from the University of Sydney Human Research Ethics Committee. The posterior eye cup was fixed in 2% paraformaldehyde and the retina dissected and processed with a rabbit antiserum against human melanopsin protein (kindly provided by Dr. King-Wai Yau). In addition vibratome sections of retinal pieces were double labeled with the antiserum against melanopsin and a postsynaptic marker.
Two types of melanopsin-expressing cells were distinguished based on their dendritic stratification: inner stratifying and outer stratifying types. Outer stratifying cells make up on average 60% of all melanopsin-expressing cells. About 80% of the outer melanopsin cells have their soma displaced to the inner nuclear. 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 cells ranges from 250 µm (near the fovea) to 1000 µm in peripheral retina. Melanopsin cells have an average peak density of about 20 to 40 cells per /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.
Our results support previous findings showing that melanopsin-expressing cells in human retina form two morphological populations. These populations have higher average densities then their counterparts in macaque retina (Liao et al., 2016). In addition our findings indicate that outer and inner cells are differentially distributed across the retina, namely that there might be higher proportions of inner stratifying cells in central than in peripheral retina.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.
This PDF is available to Subscribers Only