Extinction and recovery of an avoidance memory impaired by scopolamine

Physiol Behav. 2017 Mar 15:171:192-198. doi: 10.1016/j.physbeh.2016.12.042. Epub 2017 Jan 6.


Pre-training administration of scopolamine (SCP) resembles situations of cholinergic dysfunction, leading to memory impairment of mice trained in an inhibitory avoidance task. We suggest here that SCP does not impair memory formation, but acquisition is affected in a way that reduces the strength of the stored memory, thus making this memory less able to control behavior when tested. Hence, a memory trace is stored, but is poorly expressed during the test. Although weakly expressed, this memory shows extinction during successive tests, and can be strengthened by using a reminder. Our results indicate that memories stored under cholinergic dysfunction conditions seem absent or lost, but are in fact present and experience common memory processes, such as extinction, and could be even recovered by using appropriate protocols.

MeSH terms

  • Animals
  • Avoidance Learning / drug effects*
  • Cholinergic Antagonists / toxicity*
  • Disease Models, Animal
  • Dose-Response Relationship, Drug
  • Electroshock / adverse effects
  • Extinction, Psychological / drug effects
  • Extinction, Psychological / physiology*
  • Male
  • Memory Disorders / chemically induced*
  • Memory Disorders / physiopathology*
  • Mice
  • Reaction Time / drug effects
  • Recovery of Function / drug effects
  • Recovery of Function / physiology
  • Scopolamine / toxicity*


  • Cholinergic Antagonists
  • Scopolamine