ON-OFF amacrine cells in cat retina

J Comp Neurol. 1996 Jan 15;364(3):556-566. doi: 10.1002/(SICI)1096-9861(19960115)364:3<556::AID-CNE12>3.0.CO;2-N.


We studied the morphology, photic responses, and synaptic connections of ON-OFF amacrine cells in the cat retina by penetrating them with intracellular electrodes, staining them with horseradish peroxidase, and examining them with the electron microscope. In a sample of seven cells, we found two different morphological types: the A19, which ramifies narrowly in stratum 2 (sublamina a) of the inner plexiform layer, and the A22, which ramifies mostly in stratum 4 (sublamina b) but extends some dendrites to sublamina a. Both of these cell types have axon-like processes that extend > 800 microns from the conventional dendritic arbor. ON-OFF amacrine cells in our sample had receptive fields (1.7 +/- 0.3 mm diameter) that were broader than their dendritic arbors (425 +/- 35 microns diameter) and that extended over the region of axon-like processes. In addition, we found many features in common with ON-OFF amacrine cells in poikilotherm vertebrates: a broad receptive field without surround antagonism, two sizes of spike-like events, narrow dynamic range (1 log unit intensity), and excitatory postsynaptic potentials at light on and light off. Two A19 amacrine cells were examined in the electron microscope: most synaptic inputs (93 and 76%, respectively) to either cell were from amacrine cells, with minor inputs from cone bipolar cells. Synaptic outputs were to bipolar, amacrine, and ganglion cells, including the OFF-alpha cell.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Axons / physiology
  • Axons / ultrastructure
  • Cats
  • Dendrites / physiology
  • Dendrites / ultrastructure
  • Electrophysiology
  • Evoked Potentials, Visual / physiology
  • Histocytochemistry
  • Horseradish Peroxidase
  • Microscopy, Electron
  • Photic Stimulation
  • Retina / cytology
  • Retina / physiology*
  • Retina / ultrastructure
  • Retinal Cone Photoreceptor Cells / physiology
  • Synapses / physiology
  • Synapses / ultrastructure
  • Visual Fields / physiology


  • Horseradish Peroxidase