Butt AE, Allen K, Arthur K, Cole C, Cook S, Gerth A, Hoichi M, Long C, Noble M, Rea T, Rogers J (2000) A test of negative patterning reveals selective impairment in configural association learning in rats with 192 IgG-saporin lesions of the nucleus basalis magnocellularis. Neuroscience 2000 Abstracts 563.5. Society for Neuroscience, New Orleans, LA.
Summary: We have previously argued that the nucleus basalis magnocellularis (NBM) is selectively involved in configural and not simple association learning, although the experiments used to support our position have involved comparatively non-selective NBM lesions. In the current experiment, rats with bilateral lesions of the NBM created using the highly selective cholinergic immunotoxin 192 IgG-saporin (n = 6) and sham-operated rats (n = 6) were trained in the negative patterning paradigm. In this task, operant responses made in the presence of a light (L) or a tone (T) are reinforced (+) when either stimulus is presented alone, but responses made when these stimuli are presented in compound (LT) are not reinforced (-). We hypothesized that rats in the NBM lesion group would learn to respond to L+ and T+, which requires the ability to learn simple associations, but would fail to learn to withhold responding to the LT- compound, which requires the ability to form configural associations. Responding to L+ and T+ was normal in the NBM lesion group, suggesting an intact ability to learn simple associations, but these animals failed to learn to discriminate between the reinforced stimulus elements L+ and T+ and the nonreinforced compound LT-, suggesting an impairment in configural association learning. The greater level of LT- responding observed in the NBM lesion group did not reflect an overall response disinhibition, as responding during the inter-trial interval did not differ between groups.
Related Products: 192-IgG-SAP (Cat. #IT-01)