LAMPREY GANGLION-CELLS CONTACT PHOTORECEPTOR CELLS

Lamprey retinal ganglion cells are localized in two separate layers: t hose close to the vitreous and those at the junction between the inner nuclear and inner plexiform layers, including some others in the inne r nuclear layer, close to the photoreceptor cell layer. Whereas most g anglion cell dendrites arborize in the inner plexiform layer and conta ct amacrine, bipolar and retinopetal cell profiles, some of them, loca ted in the inner nuclear layer, ascend radially through the outer plex iform layer and establish contacts with photoreceptor cells. This gang lion cell type might correspond to the biplexiform ganglion cells alre ady described in gnathostome vertebrate species and could provide a fa stforward signal from photoreceptors to ganglion cells, bypassing the usual bipolar cell interneuron. (C) 1998 Elsevier Science Ireland Ltd. All rights reserved.