Post-training intracranial self-stimulation facilitates a hippocampus-dependent task

Behav Brain Res. 2005 May 7;160(1):141-7. doi: 10.1016/j.bbr.2004.11.025. Epub 2005 Jan 6.

Abstract

Previous research has shown that post-training intracranial self-stimulation facilitates implicit or procedural memory. To know whether it can also facilitate explicit memory, post-training intracranial self-stimulation was given to Wistar rats immediately after every daily session of a delayed spatial alternation task that seems to depend on the integrity of the hippocampal memory system. We tested the effects of intracranial self-stimulation in three consecutive learning phases which tried to make the task progressively more difficult: 10 s delay (D10 phase), 30 s delay (D30 phase), and inverting the starting position of the animals to make their response more dependent on allocentric cues (INV phase). Every phase finished when each rat achieved a fixed learning criterion. Intracranial self-stimulation facilitated the flexible expression of the learned response (INV phase). That is, when the starting position was randomly inverted, only the rats that received intracranial self-stimulation maintained the performance level acquired in the previous training phases. Changing the starting position reduced the correct performance of the non-treated subjects, which need more training sessions to achieve the learning criterion and made less correct responses than treated rats. These findings show that post-training intracranial self-stimulation can facilitate hippocampus-dependent memories.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Avoidance Learning / physiology
  • Avoidance Learning / radiation effects*
  • Behavior, Animal / radiation effects
  • Electric Stimulation / methods
  • Hippocampus / physiology*
  • Hippocampus / radiation effects
  • Male
  • Maze Learning / physiology
  • Maze Learning / radiation effects
  • Memory / physiology*
  • Motor Activity / physiology
  • Practice, Psychological*
  • Rats
  • Rats, Wistar
  • Retention, Psychology / physiology
  • Retention, Psychology / radiation effects
  • Self Stimulation*
  • Space Perception / physiology
  • Space Perception / radiation effects
  • Stereotaxic Techniques
  • Time Factors