Reciprocal changes in center and surrounding S potentials of fish retina in response to dopamine

Effects of dopamine (DA) were examined on the intracellularly recorded potential from horizontal cells in the fish (Eugerres plumieri) rentina. DA (100 micron in the perfusate) augmented the center S potential in a response to a spot illumination and attenuated the surrounding S potential to an annular light by approximately 40%. These reciprocal changes in the S potentials were associated with a slight depolarization (2.5 mV) of the horizontal cell, and were reversible in 10-15 min. The results indicate that DA at this concentration does not affect directly the synaptic transmission from photoreceptors to horizontal cells, while it appears to interfere selectively with the lateral propagation of an S potential. The effects of DA observed may represent an aspect of function of DA-containing interplexiform cells in the retina.