‘Starburst’ amacrine cells and cholinergic neurons: mirror-symmetric ON and OFF amacrine cells of rabbit retina

Golgi-impregnated 'starburst' amacrine cells share significant morphological features with cholinergic neurons in rabbit retina. They are mirror-symmetrical about the a/b (OFF/ON) sublaminar border of the inner plexiform layer. Type a starburst amacrines have cell bodies in the amacrine cell layer and dendrites in sublamina a, while type b cells have their cell bodies in the ganglion cell layer and dendrites in sublamina b of the inner plexiform layer (IPL). The two levels of narrow dendritic stratification are precisely those demonstrated by Masland and Mills for cholinergic amacrine cells. The morphological evidence indicates that the duality of ON and OFF pathways is served separately by type b (displaced) and type a starburst amacrine cells, respectively.