Differential effects of nucleus basalis lesions in young adult and aging rats

Neurobiol Aging. 1999 Jul-Aug;20(4):381-93. doi: 10.1016/s0197-4580(99)00025-1.

Abstract

To characterize age-related changes in frontal cortical plasticity, we assessed maze learning and frontal cortical pharmacology in young adult, middle-aged, and aged rats. Rats received either ibotenic acid or sham lesions of the nucleus basalis magnocellularis (NBM) and were then trained on a radial maze task. After training, we assessed [3H]desmethylimipramine (DMI), [3H]muscimol, [3H]AMPA, and [3H]QNB binding using quantitative autoradiography. Both middle-aged and aged rats were impaired on the radial maze task. DMI binding was increased in both middle-aged and aged rats, while QNB binding was decreased in aged rats. While lesions impaired maze performance at all ages, middle-aged and aged rats showed more profound lesion-induced deficits. Lesions increased GABA, and AMPA receptor binding in young adult rats only. These lesion-induced changes may reflect a compensatory response that is lost with advancing age.

Publication types

  • Comparative Study
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Aging / physiology*
  • Animals
  • Basal Nucleus of Meynert / physiopathology*
  • Brain Injuries / physiopathology
  • Excitatory Amino Acid Antagonists / pharmacology
  • Frontal Lobe / cytology
  • Frontal Lobe / metabolism
  • Frontal Lobe / physiopathology
  • Ibotenic Acid / pharmacology
  • Male
  • Maze Learning / physiology
  • Memory Disorders / physiopathology
  • Nerve Degeneration / chemically induced
  • Neuronal Plasticity / physiology
  • Neurotransmitter Agents / metabolism
  • Radioligand Assay
  • Rats
  • Rats, Long-Evans

Substances

  • Excitatory Amino Acid Antagonists
  • Neurotransmitter Agents
  • Ibotenic Acid