Three forms of spatial temporal feedforward inhibition are common to different ganglion cell types in rabbit retina

J Neurophysiol. 2010 May;103(5):2618-32. doi: 10.1152/jn.01109.2009. Epub 2010 Mar 10.

Abstract

There exist more than 30 different morphological amacrine cell types, but there may be fewer physiological types. Here we studied the amacrine cell outputs by measuring the temporal and spatial properties of feedforward inhibition to four different types of ganglion cells. These ganglion cells, each with concentric receptive field organization, appear to receive a different relative contribution of the same three forms of feed-forward inhibition, namely: local glycinergic, local sustained GABAergic, and broad transient GABAergic inhibition. Two of these inhibitory components, local glycinergic inhibition and local sustained GABAergic inhibition were localized to narrow regions confined to the dendritic fields of the ganglion cells. The third, a broad transient GABAergic inhibition, was driven from regions peripheral to the dendritic area. Each inhibitory component is also correlated with characteristic kinetics expressed in all ganglion cells: broad transient GABAergic inhibition had the shortest latency, local glycinergic inhibition had an intermediate latency, and local sustained GABAergic inhibition had the longest latency. We suggest each of these three inhibitory components represents the output from a distinct class of amacrine cell, mediates a specific visual function, and each forms a basic functional component for the four ganglion cell types. Similar subunits likely exist in the circuits of other ganglion cell types as well.

MeSH terms

  • Action Potentials
  • Amacrine Cells / cytology
  • Amacrine Cells / drug effects
  • Amacrine Cells / physiology
  • Animals
  • Dendrites / drug effects
  • Dendrites / physiology
  • Evoked Potentials, Visual / drug effects
  • Glycine / metabolism
  • Immunohistochemistry
  • In Vitro Techniques
  • Kinetics
  • Membrane Potentials / drug effects
  • Neural Inhibition / drug effects
  • Neural Inhibition / physiology*
  • Patch-Clamp Techniques
  • Photic Stimulation
  • Rabbits
  • Retina / cytology
  • Retina / drug effects
  • Retina / physiology
  • Retinal Ganglion Cells / cytology
  • Retinal Ganglion Cells / drug effects
  • Retinal Ganglion Cells / physiology*
  • Time Factors
  • Vision, Ocular / drug effects
  • Vision, Ocular / physiology
  • gamma-Aminobutyric Acid / metabolism

Substances

  • gamma-Aminobutyric Acid
  • Glycine