Nucleus accumbens lesions impair context, but not cue, conditioning in rats

• Published in: Neuroreport Vol. 8; no. 11; pp. 2477 - 2481
• Main Authors: Riedel, Gernot, Harrington, Nicholas R, Hall, Geoffrey, Macphail, Euan M
• Format: Journal Article
• Language: English
• Published: Hagerstown, MD Lippincott-Raven Publishers 28-07-1997; Lippincott Williams and Wilkins
• Subjects: Acoustic Stimulation; Anatomical correlates of behavior; Animals; Behavioral psychophysiology; Biological and medical sciences; Brain Mapping; Conditioning, Operant - physiology; Electrolysis; Fundamental and applied biological sciences. Psychology; Hippocampus - physiology; Learning - physiology; Male; Motor Activity; Movement; Nucleus Accumbens - physiology; Psychology. Psychoanalysis. Psychiatry; Psychology. Psychophysiology; Rats; Rats, Inbred Strains; Reaction Time; Context; Rat; Rodentia; Central nervous system; Basal ganglion; Classical conditioning; Learning; Nucleus accumbens; Vertebrata; Mammalia; Acquisition process; Acoustic stimulus; Animal; Lesion; Conditioned aversion; Hippocampus; Brain (vertebrata)
• ISSN: 0959-4965; 1473-558X
• DOI: 10.1097/00001756-199707280-00013

PREVIOUS work has provided evidence of a role for the hippocampal formation in contextual as opposed to cue conditioning. Similar deficits have been observed after transection of the fimbria/fornix, part of which consists of the hippocampal-nucleus accumbens (N.Acc) connection arising from both the dorsal and ventral subiculum. By means of electrolytic lesions of the N.Acc, we showed that the subiculo-accumbens projection appears to participate in aversive conditioning to context, but not to a cue (tone). Freezing, measured as an index of learning, in the experimental context was greatly reduced in animals with lesions of the N.Acc, as compared with sham-operated controls. No difference was found in freezing to a distinct tone. These data lend further support to the notion that the N.Acc is an important interface between limbic structures and motor output.