Comparative effects of cholinergic drugs and lesions of nucleus basalis or fimbria-fornix on delayed matching in rats

Psychopharmacology (Berl). 1985;87(3):357-63. doi: 10.1007/BF00432721.

Abstract

To provide a more specific test of memory impairments following lesions to central cholinergic systems, rats were trained on an operant delayed matching task. Ibotenic acid lesions of the nucleus basalis produced a disruption of performance at all delay intervals (a parallel downward shift in the delay-performance curve). By contrast, fimbria-fornix transections had no effects at short delays, but produced a progressively greater impairment as the delays lengthened (an increased downward slope of the delay-performance curve). Scopolamine produced a dose-dependent disruption of performance, apparent at the shortest delays but greater at longer delays, that was similar to the two lesion deficits combined, whereas physostigmine induced a mild but significant enhancement of performance. The results support the hypothesis that disruption of hippocampal circuitries, including cholinergic afferents via the fimbria-fornix, produces short-term or working memory impairments, whereas disruption of the cortical cholinergic system implicates more stable long-term aspects of task performance. Peripherally administered cholinergic drugs produce both types of effect and thus may influence both systems.

MeSH terms

  • Animals
  • Basal Ganglia / physiology*
  • Brain Mapping
  • Cerebral Cortex / physiology
  • Cholinergic Fibers / physiology
  • Female
  • Hippocampus / physiology
  • Memory / physiology*
  • Methamphetamine / pharmacology
  • Neural Pathways / physiology
  • Physostigmine / pharmacology
  • Rats
  • Rats, Inbred Strains
  • Scopolamine / pharmacology
  • Septum Pellucidum / physiology*
  • Substantia Innominata / physiology*

Substances

  • Methamphetamine
  • Physostigmine
  • Scopolamine