A combined Golgi and autoradiographic study of (3H)glycine-accumulating amacrine cells in the cat retina.

Golgi techniques were combined with electron microscopic autoradiography to identify four subpopulations of amacrine cell in the cat retina which accumulate (3H)glycine. These subpopulations include types A3, A4, A7(AII), and A8 amacrine cells. All are narrow-field cells with dendritic spreads of less than 100 micron. Quantification of silver grains showed that each subpopulation exhibits a consistent affinity for (3H)glycine. Type A8 cells were found to have the greatest affinity with normalized grain densities of 0.88-1.0 grains/micron 2 on a scale in which 1.0 represents the most heavily labeled cell. Type A4 cells were moderately labeled with grain densities ranging from 0.40 to 0.68 grains/micron 2. A7(AII) and A3 amacrines were lightly labeled with grain densities of 0.33-0.35 grains/micron 2 and 0.28-0.30 grains/micron 2, respectively.