AII (Rod) amacrine cells form a network of electrically coupled interneurons in the mammalian retina

Neuron. 2002 Mar 14;33(6):935-46. doi: 10.1016/s0896-6273(02)00609-8.

Abstract

AII (rod) amacrine cells in the mammalian retina are reciprocally connected via gap junctions, but there is no physiological evidence that demonstrates a proposed function as electrical synapses. In whole-cell recordings from pairs of AII amacrine cells in a slice preparation of the rat retina, bidirectional, nonrectifying electrical coupling was observed in all pairs with overlapping dendritic trees (average conductance approximately 700 pS). Coupling displayed characteristics of a low-pass filter, with no evidence for amplification of spike-evoked electrical postsynaptic potentials by active conductances. Coincidence detection, as well as precise temporal synchronization of subthreshold membrane potential oscillations and TTX-sensitive spiking, was commonly observed. These results indicate a unique mode of operation and integrative capability of the network of AII amacrine cells.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Action Potentials / physiology
  • Amacrine Cells / cytology
  • Amacrine Cells / metabolism*
  • Animals
  • Gap Junctions / metabolism*
  • In Vitro Techniques
  • Nerve Net / cytology
  • Nerve Net / physiology*
  • Patch-Clamp Techniques
  • Rats
  • Retina / cytology
  • Retina / physiology*
  • Synaptic Transmission / physiology
  • Time Factors