| Summary: | The experiments in this thesis investigated the neuropharmacology of memory in the caudate nucleus, using the conditioned emotional response (CER) with visual and olfactory conditioned stimuli (CS). === In experiment 1, post-training, intrastriatal microinjections of both amphetamine and LY 171555, but not SKF 38393: (1) into the posteroventral area improved memory of a visual, but not an olfactory, CER; (2) into the ventrolateral area improved memory of an olfactory, but not a visual, CER. In experiment 2, sulpiride, but not SCH 23390, blocked the memory improving effect of amphetamine. These findings are consistant with the hypothesis that dopamine D2 receptor stimulation mediates the memory enhancement effect of amphetamine in the neostriatum. === In three experiments on a visual CER, pre-training intrastriatal micro-injections of scopolamine impaired acquisition; post-training micro-injections improved consolidation; and pre-testing micro-injections impaired retrieval. These findings are consistant with the hypothesis that striatal muscarinic receptor stimulation mediates some aspects of acquisition and retrieval of sensory-motor memory, and that blockade of these receptors following training has an effect on memory consolidation similar to that of D2-receptor stimulation. === In experiment 6, destruction of the dopaminergic nigrostriatal neurons abolished the memory improving effect of intrastriatal post-training micro-injections of scopolamine and AFDX-384, a specific muscarinic M2 antagonist. These results suggest that the post-training memory improvement produced by muscarinic blockade may be mediated by an M2 receptor, known to be located on dopaminergic nigro-striatal terminals.
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