Frick KM, Kim JJ, Baxter MG (2002) Effect of 192-IgG saporin lesions of the entire basal forebrain on emotional and spatial learning. Neuroscience 2002 Abstracts 379.1. Society for Neuroscience, Orlando, FL.
Summary: Scopolamine administration studies suggest that acetylcholine appears to be important for acquisition of contextual fear conditioning (FC), but its involvement in consolidation of fear remains a matter of debate. We examined the role of the basal forebrain cholinergic system in emotional learning and memory by testing male Sprague-Dawley rats with 192 IgG-saporin lesions of basal forebrain cholinergic neurons in contextual and tone FC. Lesions were made either 7 days before (n=10) or one day after (n=10) FC and targeted all basal forebrain nuclei; sham-operated rats (n=5 per condition) served as a comparison. Spatial learning in a one-day water maze task provided a comparison for effects of the lesions on FC. Pretraining lesions had no effect on freezing to tone or context. Posttraining lesions produced a mild impairment in freezing to context, but had no effect on freezing to tone. Both groups were impaired in production of 22 kHz ultrasonic vocalization (USV) associated with fear. Performance on water maze training trials was surprisingly impaired in lesioned rats, although this impairment did not interact with training block and probe trial performance was unimpaired, suggesting that it did not reflect a learning impairment. Radioenzymatic assays of choline acetyltransferase activity in neocortex and hippocampus revealed substantial (>80%) decreases in cholinergic input. These data suggest that conditioned fear-induced USV is more sensitive to the loss of basal forebrain cholinergic neurons than conditioned fear-induced freezing.
Related Products: 192-IgG-SAP (Cat. #IT-01)