Accession Number:

ADA181397

Title:

Neurochemical Mechanisms Mediating Recovery of Function

Descriptive Note:

Annual rept. 1 Aug 1983-31 Jul 1984

Corporate Author:

JOHNS HOPKINS UNIV BALTIMORE MD DEPT OF PSYCHOLOGY

Personal Author(s):

Report Date:

1984-11-01

Pagination or Media Count:

37.0

Abstract:

We investigated whether the type of motivation, reinforcement, response-reinforcement contingency, or the response itself was influenced by ibotenic acid lesions in the basal forebrain. The tasks were postoperative acquisition of a win-stay spatial discrimination in a T-maze, a win-shift spatial discrimination on a radial arm maze, active avoidance in a shuttle box, and passive avoidance in a shuttle box. Rats with lesions had significantly fewer trials to reach criterion in the active avoidance task, and took significantly more trials to reach criterion in the passive avoidance task. These results indicated that equivalent behavioral changes are obtained from lesions in the nucleus basalis magnocellularis and the medial septal area in tasks that vary in motivation and reinforcement contingencies. Investigations of changes in various biochemical parameters choline acetyltransferase, serotonin receptor binding, biogenic amine and metabolite levels in cortex, caudate and hippocampus indicate that the ibotenic acid lesions are selective for the cholinergic system when used in the described manner. Microinfusion experiments indicate that enkephalinergic, GABAergic, and possibly glutamatergic receptors are located on basal forebrain cholinergic neurons. We have begun to understand the importance of the basal forebrain cholinergic system for memory and cognition and have preliminary data on how to produce a recovery of function following exposure to toxins which damage this brain region.

Subject Categories:

  • Biochemistry
  • Toxicology
  • Pharmacology

Distribution Statement:

APPROVED FOR PUBLIC RELEASE