Synaptic connections between neurons in living slices of the larval tiger salamander retina.

Synaptic connections between retinal cells were studied by recording simultaneously from pre- and postsynaptic cells in the retinal slice preparation. The time course and waveform of the pre- and postsynaptic light responses were monitored, and the postsynaptic voltage responses to presynaptic current injection were measured. Results obtained provide direct evidence showing that the rod-HBC and rod-HC synapses are sign-preserving, and the rod-DBC, HC-HBC and amacrine-DBC synapses are sign-inverting. Moreover, the synaptic delays between rods and bipolar cells are shorter than that between rods and horizontal cells. The methodology of making retinal slices and the subsequent recording and stimulation procedures are described. The advantages of the retinal slice preparation and its potential in retinal research are discussed.