A combined Golgi and autoradiographic study of 3H-glycine-accumulating cone bipolar cells in the cat retina.
Morphological subclasses of cone bipolar cells in the cat retina were studied in Golgi preparations and through the combination of Golgi impregnation with quantitative electron-microscopic autoradiography of 3H-glycine accumulation. Camera lucida drawings, computer-assisted rotations, and radial sections provided the morphological details used in assigning individual cells to morphologically defined subclasses. Selected Golgi-impregnated cells from retinas preloaded with 3H-glycine were sectioned for autoradiographic analysis. Grain densities were quantitated and compared on a normalized scale with the labeling of amacrine cells with 3H-glycine. Eleven types of cone bipolar cells were identified, 6 with axon terminals ramifying in sublamina a and 5 with axons terminating in sublamina b. Of these cells, types CBb2 and CBb5 showed the highest affinity for glycine, with labeling at 41 and 38% with respect to the most heavily labeled amacrine cells. Types CBb1, CBb3, CBa2, and CBa6 were labeled at approximately 20% of maximal labeling. The accumulation of glycine by these cells suggests that they may be involved in providing inhibitory input to the inner retina.
D000818:Animals; D001345:Autoradiography; D001369:Axons / Q000648:ultrastructure; D002415:Cats; D003712:Dendrites / Q000648:ultrastructure; D005998:Glycine / Q000378:metabolism*; D008854:Microscopy, Electron; D009474:Neurons / Q000648:ultrastructure*; D010781:Photography / Q000379:methods; D012160:Retina / Q000166:cytology* / Q000378:metabolism; D013194:Staining and Labeling / Q000379:methods
D005998:Glycine