Contrast enhancement: a physiological effect of striatal dopamine?

Cell Tissue Res. 2004 Oct;318(1):93-106. doi: 10.1007/s00441-004-0929-z. Epub 2004 Jul 28.

Abstract

Dopamine functions as an important neuromodulator in the dorsal striatum and ventral striatum/nucleus accumbens. Evidence is accumulating for the idea that striatal neurons compete with each other for control over the animal's motor resources, and that dopamine plays an important modulatory role that allows a particular subset of neurons, encoding a specific behavior, to predominate in this competition. One means by which dopamine could facilitate selection among competing neurons is to enhance the contrast between stronger and weaker excitations (or to increase the "signal to noise ratio" among neurons, where the firing of the most excited neurons is assumed to transmit signal and the firing of the least excited to transmit noise). Here, we review the electrophysiological evidence for this hypothesis and discuss potential cellular mechanisms by which dopamine-mediated contrast enhancement could occur.

Publication types

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

MeSH terms

  • Animals
  • Corpus Striatum / cytology
  • Corpus Striatum / physiology*
  • Dopamine / physiology*
  • Neuronal Plasticity / physiology*
  • Neurons / physiology*

Substances

  • Dopamine