Response properties of a unique subtype of wide-field amacrine cell in the rabbit retina

Stewart A. Bloomfield, Béla Völgyi

Research output: Article

23 Citations (Scopus)

Abstract

We studied the morphology and physiology of a unique wide-field amacrine cell in the rabbit retina. These cells displayed a stereotypic dendritic morphology consisting of a large, circular and monostratified arbor that often extended over 2 mm. Their responses contained both somatic and dendritic sodium spikes suggesting active propagation of synaptic signals within the dendritic arbor. This idea is supported by the enormous size of their ON-OFF receptive fields. Interestingly, these cells exhibited separate ON and OFF receptive fields that, while concentric, were vastly different in size. Whereas the ON receptive field of these cells extended nearly 2 mm, the OFF receptive field was typically 75% smaller. Blockade of voltage-gated sodium channels with QX-314 dramatically reduced the large ON receptive field, but had little effect on the smaller OFF receptive field. These results indicate a spatial disparity in the location of on- and off-center bipolar cell inputs to the dendritic arbor of wide-field amacrine cells. In addition, the active propagation of signals suggests that synaptic inputs are integrated both locally and globally within the dendritic arbor.

Original languageEnglish
Pages (from-to)459-469
Number of pages11
JournalVisual neuroscience
Volume24
Issue number4
DOIs
Publication statusPublished - júl. 1 2007

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ASJC Scopus subject areas

  • Physiology
  • Sensory Systems

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