Differential effects of nucleus basalis lesions in young adult and aging rats.
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.
Wellman
C L
CL
Department of Psychology, Indiana University, Bloomington 47405, USA. wellmanc@indiana.edu
Pelleymounter
M A
MA
D000375:Aging / Q000502:physiology*; D000818:Animals; D020532:Basal Nucleus of Meynert / Q000503:physiopathology*; D001930:Brain Injuries / Q000503:physiopathology; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D005625:Frontal Lobe / Q000166:cytology / Q000378:metabolism / Q000503:physiopathology; D007051:Ibotenic Acid / Q000494:pharmacology; D008297:Male; D018782:Maze Learning / Q000502:physiology; D008569:Memory Disorders / Q000503:physiopathology; D009410:Nerve Degeneration / Q000139:chemically induced; D009473:Neuronal Plasticity / Q000502:physiology; D018377:Neurotransmitter Agents / Q000378:metabolism; D011869:Radioligand Assay; D051381:Rats; D020318:Rats, Long-Evans
D018691:Excitatory Amino Acid Antagonists; D018377:Neurotransmitter Agents; D007051:Ibotenic Acid