Temporary inactivation of the dorsal hippocampus induces a transient impairment in retrieval of aversive memory

Behav Brain Res. 2007 Jun 18;180(2):113-8. doi: 10.1016/j.bbr.2007.02.031. Epub 2007 Feb 25.

Abstract

The reconsolidation hypothesis, which predicts that consolidated memories become labile and sensitive to amnestic agents upon reactivation, has been one of the most debated topics in memory research over recent years. One of the main criticisms to this hypothesis is the fact that some studies have shown the effects of "reconsolidation blockade" to be transient. Here we show that muscimol inactivation of the dorsal hippocampus following memory reactivation produces a reversible impairment of step-down inhibitory avoidance memory in rats. Moreover, we show that the reversal of this effect is dependent on the passage of time, and not on repeated testing. The implications of the findings to the interpretation of the phenomenon of transient retrieval impairment induced by post-reactivation pharmacological interventions on memory systems are discussed.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Avoidance Learning / drug effects
  • Avoidance Learning / physiology*
  • Behavior, Animal
  • GABA Agonists / pharmacology
  • Hippocampus / drug effects
  • Hippocampus / physiology*
  • Inhibition, Psychological*
  • Male
  • Memory Disorders / chemically induced
  • Memory Disorders / physiopathology*
  • Muscimol / pharmacology
  • Rats
  • Rats, Wistar
  • Reaction Time / drug effects
  • Reaction Time / physiology
  • Statistics, Nonparametric
  • Time Factors

Substances

  • GABA Agonists
  • Muscimol