Hippocampal-dependent learning and experience-dependent activation of the hippocampus are preferentially disrupted by ethanol

K. R. Melia, Andrey Ryabinin, K. P. Corodimas, M. C. Wilson, J. E. LeDoux

Research output: Contribution to journalArticle

109 Scopus citations

Abstract

A classical fear conditioning paradigm was used to examine the effect of acute ethanol on the acquisition of context conditioning, a hippocampal- dependent associative task, and tone conditioning, a hippocampal-independent task. Administration of ethanol before the presentation of seven tone shock pairings severely disrupted the acquisition of context conditioning, but had only a slight effect on tone conditioning, when conditioned fear was measured 48 h later. This effect was dose dependent: a dose of 0.5 g/kg had no effect on either context or tone conditioning, while doses of 1.0 and 1.5 g/kg disrupted context conditioning by 78-86%, and tone conditioning by 9- 17%. Subsequent experiments indicated that ethanol's preferential effect on context conditioning could not be attributed to the fact that context conditioning is weaker than tone conditioning, ethanol-induced changes in motivational state or state-dependent learning. The effect of ethanol on stimulus-reduced increases in hippocampal and neocortical expression of c- fos mRNA, a marker for changes in metabolic neuronal activity, was also examined. Ethanol completely blocked the induction of hippocampal c-fos mRNA by exposure to the conditioning context alone or seven tone shock pairings, but only attenuated neocortical responses to these stimuli. Together, these results suggest that ethanol disrupts hippocampal-dependent learning by preferentially impairing stimulus processing at the level of the hippocampus.

Original languageEnglish (US)
Pages (from-to)313-322
Number of pages10
JournalNeuroscience
Volume74
Issue number2
DOIs
Publication statusPublished - Jul 19 1996
Externally publishedYes

    Fingerprint

Keywords

  • alcohol
  • c-fos
  • context
  • fear conditioning
  • memory

ASJC Scopus subject areas

  • Neuroscience(all)

Cite this