Lesions of the prelimbic-infralimbic cortices in rats do not disrupt response selection processes but induce delay-dependent deficits: evidence for a role in working memory?

Behav Neurosci. 1999 Oct;113(5):941-55. doi: 10.1037//0735-7044.113.5.941.


Effects of neurotoxic lesions of the prelimbic-infralimbic cortex (PL-IL) were examined in rats performing 2 conditional tasks. PL-IL-lesioned rats showed normal acquisition of a visuospatial conditional discrimination in a Y maze as well as a tone-light conditional discrimination in an operant chamber, indicating that the PL-IL is not necessary for response selection processes. When the working memory load was subsequently increased in the tone-light conditional discrimination, rats with PL-IL lesions showed a delay-dependent disruption of performance. This suggests a role of the PL-IL in some working memory processes. However, the present results, considered along with previous studies, suggest that the PL-IL does not seem to be directly involved in the processes necessary to maintain specific items over a delay period but rather in the planning of forthcoming behavioral responses on the basis of previously acquired information.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Conditioning, Operant / physiology*
  • Discrimination Learning / physiology*
  • Excitatory Amino Acid Agonists
  • Ibotenic Acid
  • Limbic System / drug effects
  • Limbic System / physiology*
  • Male
  • Maze Learning / physiology*
  • Memory / physiology*
  • Prefrontal Cortex / drug effects
  • Prefrontal Cortex / physiology*
  • Rats
  • Rats, Sprague-Dawley


  • Excitatory Amino Acid Agonists
  • Ibotenic Acid