Temporal dissociation of neurotensin/neuromedin N mRNA expression in topographically separate subsets of rat striatal neurons following administration of haloperidol.

Abstract

The expression of the neurotensin/neuromedin N gene in the rat caudate-putamen was studied at 7 and 24 h following the administration of haloperidol using a riboprobe and non-isotopic in situ hybridization histochemistry. As has been reported by others, expression of neurotensin/neuromedin N mRNA in the dorsolateral quadrant of the caudate-putamen was undetectable in controls, robust at 7 h and minimally detectable at 24 h following haloperidol administration. In the dorsomedial and ventrolateral quadrants of the caudate-putamen, barely detectable basal expression of neurotensin/neuromedin N mRNA observed in controls was conspicuously enhanced at 24 h following administration of haloperidol both in terms of numbers of hybridized neurons, which were about 200% of control values, and the amount of chromogen accumulated over individual neurons. The data are consistent with at least two subpopulations of caudate-putamen neurons in which neurotensin/neuromedin N mRNA expression is differentially regulated in response to haloperidol administration.