Suppression of exploratory locomotor activity and increase in dopamine turnover following the local application of cis-flupenthixol into limbic projection areas of the rat striatum

Abstract

Recent neuroanatomical tracer studies have demonstrated the topography of 'limbic' (A10) projections into the striatum of the rat (see Introduction). The target areas include the nucleus accumbens and the ventromedial part of the neostriatum, whereas the dorsolateral part of the neostriatum does not receive such afferents. Taking this topography into account, the present results show that local application of cis-flupenthixol (10-40 micrograms/side) into the nucleus accumbens or the ventromedial, but not the dorsolateral, neostriatum produces suppression of exploratory locomotor activity in the rat. trans-Flupenthixol (40 micrograms/side) was completely ineffective when locally applied into the nucleus accumbens. Measurements of the concentrations of the dopamine metabolites 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA) at the site of injection, and in neighboring areas at different times after cis-flupenthixol administration, indicated that there was little or no diffusion of the drug from the injection sites. Much higher concentrations of DOPAC and HVA in a given area were found after systemic administration of cis-flupenthixol as compared with local application of the drug to the same area.