HISTOCHEMICAL LOCALIZATION OF DOPAMINE AND ACETYLCHOLINESTERASE ACTIVITY IN THE CARP RETINA

Abstract

Histochemical studies were conducted on the carp (C. carpio) retina to reveal the cellular localization of catecholamines (CA) and acetylcholinesterase (AchE) activity. CA was found almost exclusively in interplexiform cells, which extend processes towards both the outer and inner plexiform layers, forming dense networks at the inner nuclear and plexiform layers. The endogenous CA is dopamine (DA) and that CA-cells are dopaminergic in nature. The AchE activity was seen in a certain group of amacrine cells and in some ganglion cells, and diffusely in the inner plexiform layer and weakly in external horizontal cells. Among cells located at the innermost row of the inner nuclear layer in radial sections counterstained with methyl green, .apprx. 1 and 35% were estimated to be DA-containing interplexiform cells and AchE-positive amacrine cells, respectively. Simultaneous visualization of DA-fluorescence and AchE activity showed that AchE-positive processes are in contact with DA-fluorescent cell bodies.