Annual Meeting of the Society for Neuroscience edition:36 location:Atlanta, GA, U.S.A. date:October 14-18, 2006
We examined the expression profile of neurofilament protein in discrete cell types in whole-mounts and sections of adult cat retina using a monoclonal antibody (SMI-32), which recognizes the non-phosphorylated epitope on the high molecular weight subunit of neurofilament protein. Eight retinas from cats, binocularly deprived throughout the first 6 months of life, and 8 control cat retinas were examined. A population of large retinal ganglion cells exhibited neurofilament protein expression in their soma and the proximal parts of their dendritic arbors. These immunopositive cells were distributed throughout the retina. In retinas of control cats the immunoreactive dendrites branched specifically into sublamina-a of the inner plexiform layer, well described as the OFF inner plexiform sublamina. On the contrary, in the deprived retinas, these large ganglion cells branched throughout the entire inner plexiform layer. The density of the deprived ganglion cells was 30% higher in central retina but decreased significantly below control values (-30%) at the periphery. Moreover, deprived ganglion cells had a significantly larger diameter throughout the whole retina. In central segments of deprived retinas 65% of the SMI-32-positive cells had a diameter >40 μm, with 5% >60 μm. In controls 83% was 50 μm, with 32% >60 μm, versus 66% <50 μm in controls. In addition, in deprived retina the majority of optic nerve fibers had a beaded structure. Consequently we propose that the described adult morphology of visually-deprived ganglion cells e.g., a multi-stratification pattern, a significantly larger cell diameter, and a lower density in peripheral retina, resembles the well known immature pattern of retinal ganglion cells.