Dissociation of acute and chronic intermittent phencyclidine-induced performance deficits in the 5-choice serial reaction time task: influence of clozapine

Thomson, D.M., McVie, A., Morris, B.J. and Pratt, J.A. (2010) Dissociation of acute and chronic intermittent phencyclidine-induced performance deficits in the 5-choice serial reaction time task: influence of clozapine. Psychopharmacology, 213(4), pp. 681-695. (doi: 10.1007/s00213-010-2020-7)

Abstract

<b>Background:</b> Cognitive deficits are a core feature of schizophrenia that respond minimally to existing drugs. PCP is commonly used to model schizophrenia-like deficits preclinically although different dosing protocols may affect different domains. Here we characterise the acute, and chronic intermittent effects of PCP in the 5-choice serial reaction time task (5-CSRTT) in rats, and assess the effects of clozapine. In a novel approach, we also assess the effects of increased inhibitory load and conduct clinically relevant signal detection analysis (SDA). <b>Materials and methods:</b> The effects of acute and repeated PCP (2.58 mg/kg) treatment on attentional processes and inhibitory control were assessed during and following the chronic treatment regime in the presence or absence of chronic clozapine (20 mg/kg/day). <b>Results:</b> Thirty minutes post-PCP injection, there was an increase in anticipatory responding which disappeared after 24 h. Although, acute PCP did not change accuracy of responding or processing speed, repeated PCP revealed delayed deficits in cognitive processing speed which were partly ameliorated by clozapine. Extended inter-trial intervals increased premature responding, while SDA revealed that clozapine modified persistent PCP-induced deficits in lnBeta (a composite measure of risk taking versus caution). <b>Conclusion:</b> Acute NMDA receptor antagonism impairs inhibitory control, whereas repeated treatment produces delayed deficits in cognitive processing speed. The ability of clozapine partially to restore persistent PCP-induced deficits in processing speed and in lnBeta is consistent with clinical findings. This suggests that the enduring effects of repeated PCP treatment, combined with SDA, offers a useful, translational, approach to evaluate novel cognitive enhancers in the 5-CSRTT.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Thomson, Dr David and Pratt, Dr Judith and McVie, Mr Allan and Morris, Professor Brian
• Authors: Thomson, D.M., McVie, A., Morris, B.J., and Pratt, J.A.
• College/School: College of Medical Veterinary and Life Sciences > School of Psychology & Neuroscience
• Journal Name: Psychopharmacology
• ISSN: 0033-3158
• Published Online: 29 September 2010