Purchase this article with an account.
J Zhang, Z Yang, SM Wu; Quantitaive Analysis of GABAergic and Glycinergic Amacrine Cells in the Tiger Salamander Retina . Invest. Ophthalmol. Vis. Sci. 2002;43(13):3782.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Purpose:GABA and glycine are the major inhibitory neurotransmitters used by retinal amacrine cells in all vertebrates. The objective of this project is to study the number and distribution of GABAergic and glycinergic amacrine cells in the inner nuclear layer (INL) and ganglion cell layer (GCL) of the salamander retina. Methods:Immunocytochemical experiments were performed on salamander whole-mount retinas with confocal microscopy. Amacrine cells were triple labeled with antibodies against GABA (Chemicon, Inc), glycine (kindly provided by Dr. David Pow), and Topro3 (a nuclear dye). Ganglion cells were retrogradely labeled with Lucifer yellow (LY) and immuno-processed by LY antibodies. Displaced amacrine cells were identified as cells labeled with Topro3 but not with LY in the GCL. Results:A typical salamander retina contains about 59,000 amacrine cells in the proximal region of the INL, and about 44% of these cells are GABA-positive, 33% are glycine-positive, 3% are labeled with both GABA and glycine, and the remaining 20% are labeled with neither. The percentage of GABAergic- and glycinergic-amacrine cells increases progressively from the dorsal to ventral retina along the vertical meridian. The GCL of the salamander retina contains about 38,000 cells, and 30-40% of them are displaced amacrine cells. Ganglion cells are concentrated in the central retina with the highest ratio of ganaglion cells versus displaced amacrine cells near the optic nerve head, whereas displaced amacrine cells have higher percentage in the peripheral retina. 5% of the cells in the GCL are GABA- and/or glycine-postive (about 53% of them are GABAergic, 33% are glycinergic and 14% contain both), and the vast majority of them are displaced amacrine cells. Very few ganglion cells are weakly stained by GABA or glycine antibodies. The distribution and density profiles of GABAergic and glycinergic amacrine cells were also studied. Conclusion:This study demonstrated that in salamander retina, GABAergic and glycinergic amacrine cells account for 80% of the amacrine cells in the INL and 12.5-17% of the displaced amacrine cells in the GCL. The GABAergic and glycinergic amacrine cells are unevenly distributed in the retina, suggesting that lateral inhibition from amacrine cells to ganglion cells may be inhomogenous in the animals’ visual field.
This PDF is available to Subscribers Only