Mirza NR, Misra A, Bright JL. Different outcomes after acute and chronic treatment with nicotine in pre-pulse inhibition in Lister hooded rats.
Eur J Pharmacol 2000;
407:73-81. [PMID:
11050293 DOI:
10.1016/s0014-2999(00)00658-0]
[Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Excessive tobacco consumption by schizophrenic patients may be a form of self-medication, and nicotine in tobacco may alleviate deficits in information processing. We tested this hypothesis by determining whether nicotine (acute/chronic) would improve information processing in the rat using pre-pulse inhibition as a model. In study 1, rats were injected with nicotine 10 min prior to placement in startle chambers (0.001-0.1 or 0.03-0.3 mg/kg, s.c.). In study 2, rats were injected with either saline or nicotine (0.4 mg/kg, s.c.) for 21 consecutive days and assessed for locomotor activity, pre-pulse inhibition and changes in [3H]nicotine binding in whole brain. Acutely, nicotine had no effect on pre-pulse inhibition. By contrast, after chronic nicotine treatment, rats demonstrated a robust deficit in pre-pulse inhibition and significant increases in locomotor activity and [3H]nicotine binding. The deficit in pre-pulse inhibition after chronic treatment with nicotine may be the result of non-specific behavioural activation due to increased mesolimbic dopamine release or, possibly, nicotine may rapidly desensitize nicotinic receptors important for normal information processing.
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