Interplexiform cells of the mammalian retina and their comparison with catecholamine-containing retinal cells

Abstract

Retinal interplexiform cells have processes that branch within both the inner and outer plexiform layers. Their morphology is described from Golgi-preparations of cat, rhesus macaque and squirrel monkey retinae. Comparisons are made with similar cells, known to be catecholamine-containing, which have been observed histofluorometrically in the teleost fish and New World monkeys. It is concluded that there may be more than one pharmacological type of interplexiform cell. In addition an inner nuclear layer plexus of fibres is described for the first time from Golgi-material of the squirrel monkey's retina. Electron microscopy reveals that this plexus synapses within the inner nuclear layer on to bipolar and amacrine cells. It is compared with the catecholamine-containing inner nuclear layer plexus of New World monkeys.