Synaptic connections of the interplexiform cell in the retina of the cat.

Electron microscopy of Golgi-impregnated material and of well fixed, ultrathin serial sections has revealed the synaptic connections of interplexiform cells in cat retina. In the inner plexiform layer these cells are postsynaptic to amacrine cells and probably presynaptic to both bipolars and amacrines. In the outer plexiform layer they are presynaptic to rod and cone bipolar cells and also pre- and postsynaptic to other interplexiform cell dendrites. The interplexiform cell in cat retina appears to be concerned with feeding back information from the inner plexiform layer to the dendrites of bipolar cells in the outer plexiform layer.