Abstract
Abstract: :
Purpose: To investigate the morphology and synaptic connectivity of cholinergic neurons in the mouse retina. Methods: With immunocytochemistry using antisera against choline acetyltransferase (ChAT), whole-mount preparations and 50-µm thick vibratome sections were examined by light and electron micrroscopy. Results: ChAT labeled neurons were two populations of amacrine cells; one is amacrine cells in the inner nuclear layer and the other is displaced amacrine cells in the ganglion cell layer. Processes from ChAT labeled amacrine cells ramified in the stratum 2 of the inner plexiform layer (IPL), and those from displaced amacrine cells in the border between strata 3 and 4 of the IPL. Double labeling with antisera against ChAT and glutamic acid decarboxylase 65 or GABA demonstrated that these labeled cells formed a subpopulation of GABAergic amacrine cells. Their most frequent synaptic input was from bipolar cells in both sublaminae a and b of the IPL, followed by labeled amacrine cells and unlabeled amacrine cells. Their primary output targets were onto unlabeled amacrine cells in both laminae a and b. However, output onto ganglion cells was more frequently observed in sublamina b of the IPL. Conclusions: These results indicate that cholinergic cells of the mouse retina participate in modulating visual information via similar scheme as shown in other mammalian retina.
Keywords: retina: proximal(bipolar, amacrine, and gangli • amacrine cells • retinal connections, networks, circuitry