Chronic stress impairs spatial memory and motivation for reward without disrupting motor ability and motivation to explore

Behav Neurosci. 2006 Aug;120(4):842-51. doi: 10.1037/0735-7044.120.4.842.

Abstract

This study uses an operant, behavioral model to assess the daily changes in the decay rate of short-term memory, motivation, and motor ability in rats exposed to chronic restraint. Restraint decreased reward-related motivation by 50% without altering memory decay rate or motor ability. Moreover, chronic restraint impaired hippocampal-dependent spatial memory on the Y maze (4-hr delay) and produced CA3 dendritic retraction without altering hippocampal-independent maze navigation (1-min delay) or locomotion. Thus, mechanisms underlying motivation for food reward differ from those underlying Y maze exploration, and neurobiological substrates of spatial memory, such as the hippocampus, differ from those that underlie short-term memory. Chronic restraint produces functional, neuromorphological, and physiological alterations that parallel symptoms of depression in humans.

Publication types

  • Comparative Study

MeSH terms

  • Adrenal Glands / physiology
  • Analysis of Variance
  • Animals
  • Behavior, Animal
  • Eating / physiology
  • Exploratory Behavior / physiology*
  • Hippocampus / pathology
  • Hypnotics and Sedatives / pharmacology
  • Male
  • Maze Learning / drug effects
  • Maze Learning / physiology
  • Memory Disorders / etiology*
  • Memory Disorders / pathology
  • Motivation*
  • Motor Activity / physiology*
  • Organ Size / physiology
  • Pentobarbital / pharmacology
  • Pyramidal Cells / pathology
  • Rats
  • Rats, Sprague-Dawley
  • Reinforcement Schedule
  • Reward*
  • Stress, Physiological / complications
  • Stress, Physiological / pathology
  • Stress, Physiological / physiopathology*
  • Time Factors

Substances

  • Hypnotics and Sedatives
  • Pentobarbital