Vol. 295, Issue 1, 205-211, October 2000

Sex- and Estrous Cycle-Related Differences in the Effects of Acute Antipsychotic Drug Administration on Neurotensin-Containing Neurons in the Rat Brain¹

Becky Kinkead, Steven M. Lorch, Michael J. Owens and Charles B. Nemeroff

Laboratory of Neuropsychopharmacology, Department of Psychiatry and Behavioral Sciences, Emory University School of Medicine, Atlanta, Georgia

The effects of a single injection of haloperidol (2.0 mg/kg), a typical antipsychotic drug, on neurotensin (NT) concentrations and NT/neuromedin N (NT/NN) mRNA expression in adult female and male rats were examined. There were significant estrous cycle stage-related differences in both NT concentrations and NT/NN mRNA expression in female control rats. Although acute administration of haloperidol increased NT concentrations and NT/NN mRNA expression in the caudate/putamen and nucleus accumbens of both male and female rats, haloperidol did not increase NT/NN mRNA expression during diestrus 2 or NT concentrations during proestrus in the nucleus accumbens of female rats. These results indicate the presence of both sex- and estrous cycle-related differences in the regulation of NT-containing neurons and in the effects of antipsychotic drug administration on the NT system of the rat brain.