Animal models of behaviour: Memory, aggression and psychosis

Synaptic connectivity change is a consistent anatomical feature of memory formation. We have investigated the possibility that this is mediated by a replay of neurodevelopmental events by measuring changes in neural cell adhesion molecule sialylation state, during the acquisition and consolidation of a passive avoidance response in the adult rat. Investigations examining the influence of 5-HT1A receptors in murine agonistic and social behaviour have reported either specific or non-specific attenuation of offensive behaviour. Current results corroborate previous findings with respect to 5-HT1A receptor involvement in murine agonistic behaviour and anxiety. Data also connote that the behavioural specificity of 5-HT1A ligands should be interpreted in terms of response competition rather than solely concomitant sedation. Latent inhibition (LI) is a behavioural paradigm in which repeated non-reinforced pre-exposure to a stimulus inhibits the formation of subsequent associations to that stimulus. LI is believed to reflect the process of learning to ignore irrelevant stimuli. Since one of the central characteristics of schizophrenia is an attentional deficit, in that patients are unable to ignore irrelevant stimuli, disrupted LI has been suggested as a model for this aspect of the cognitive deficits associated with schizophrenia. We have employed the LI model to assess the potential clinical efficacy of novel neuroleptic compounds.