Basal forebrain cholinergic lesions enhance conditioned approach responses to stimuli predictive of food

• Published in: Behavioral neuroscience Vol. 112; no. 3; p. 611
• Main Authors: Olmstead, M C, Robbins, T W, Everitt, B J
• Format: Journal Article
• Language: English
• Published: United States 01.06.1998
• Subjects: alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid - adverse effects; Amphetamine - pharmacology; Analysis of Variance; Animals; Appetitive Behavior - drug effects; Appetitive Behavior - physiology; Cholinergic Fibers - drug effects; Cholinergic Fibers - physiology; Conditioning (Psychology) - drug effects; Conditioning (Psychology) - physiology; Conditioning, Classical - drug effects; Conditioning, Classical - physiology; Conditioning, Operant - drug effects; Conditioning, Operant - physiology; Consummatory Behavior - drug effects; Consummatory Behavior - physiology; Cues; Discrimination Learning - drug effects; Discrimination Learning - physiology; Dopamine Agents - pharmacology; Drug Interactions; Excitatory Amino Acid Agonists; Food; Globus Pallidus - drug effects; Globus Pallidus - physiology; Male; Motivation; Motor Activity - drug effects; Motor Activity - physiology; Quinolinic Acid; Rats; Reward; Substantia Innominata - drug effects; Substantia Innominata - physiology
• ISSN: 0735-7044
• DOI: 10.1037/0735-7044.112.3.611

This study examined the effects of lesions to different neuronal populations within the basal forebrain on reward-related learning. Rats received bilateral alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) or quinolinate lesions that preferentially destroy the cholinergic nucleus basalis magnocellularis (NBM) or noncholinergic ventral pallidal neurons, respectively. Both lesions enhanced conditioned approach responses to stimuli predictive of food but did not increase the locomotor stimulating effect of d-amphetamine. Although both lesions disrupted the discriminative control over behavior by a conditioned stimulus, they did not impair the subsequent acquisition of instrumental responding with conditioned reinforcement (CR). Indeed, both lesions were associated with an increased responding with CR following intra-accumbens infusions of d-amphetamine (0, 1, 3, 10, and 20 microg). Quinolinate lesions also increased responses on an inactive control lever. Neither lesion altered consummatory responses to food or sucrose. Results suggest that NBM lesions may disrupt the balance between cortical and subcortical dopamine levels, and/or produce a deficit in attentional mechanisms that is manifested as increased responding to specific stimuli.