Abstract
Bilateral removal of the fronto-parietal cortex of the rat resulted in decreased spontaneous multiple-unit activity recorded in the striatum of freely-moving rats. Cortical ablations changed the neuronal response in the striatum to systemic administration of dexamphetamine (2.5 mg kg i.p.) from excitation in control animals (88%) to inhibition in ablated animals (61%). Furthermore, catalepsy, induced by haloperidol, but not by morphine, was markedly attenuated after cortical ablation. These changes were accompanied by a 23% decrease in the specific binding of [3H]spiperone in the striatum. The binding of [3H]met-enkephalin was unaffected by the cortical lesions. Levels of glutamate in the striatum decreased from 8.88 ± 0.5 μmols g in control animals to 6.93 ± 0.37 μmols g after bilateral cortical ablation. On the other hand, cortical ablations did not alter the content of either the γ-aminobutyric acid or glutamine of the striatum. It is concluded that the excitatory response, observed in striatal neurons in freely-moving animals, is dependent upon an intact cerebral cortex and requires intact cortico-striatal afferents. The results further suggest that neurons in the striatum are under the tonic influence of glutamate, released from cortico-striatal afferents. Lastly, some dopamine D2 binding sites in the striatum are located on cortico-striatal afferent terminals and blockade of these striatal D2 sites may be involved in the induction of catalepsy by neuroleptic drugs.
Original language | English |
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Pages (from-to) | 1107-1114 |
Number of pages | 8 |
Journal | Neuropharmacology |
Volume | 26 |
Issue number | 8 |
DOIs | |
Publication status | Published - Aug 1987 |
ASJC Scopus Subject Areas
- Pharmacology
- Cellular and Molecular Neuroscience
PubMed: MeSH publication types
- Journal Article