DECREASED HYPOTHALAMIC SEROTONIN LEVELS IN ADULT-RATS TREATED NEONATALLY WITH CLOMIPRAMINE

Early postnatal treatment with the antidepressant drug clomipramine ha s repeatedly been shown to lead to behavioural and physiological chang es in adult rats. To provide some neurochemical correlates to these st udies we have measured a number of monoaminergic parameters in the bra ins of adult (one year old) rats that were treated twice daily with 15 mg/kg clomipramine from postnatal day 2-14. The most consistent findi ng was that the hypothalamic levels of serotonin (5-HT) were decreased and those of the dopamine metabolite dihydroxyphenylacetic acid (DOPA C) were increased in rats irrespectively whether they went through a r ange of behavioural and physiological tests or not. The numbers of bet a-adrenoceptors in the frontal cortex and of alpha(2)-adrenoceptors in the amygdala/piriform cortex were not changed. The decrease in hypoth alamic 5-HT concentrations appears to be up to now the most consistent neurochemical alteration in adult rats that were neonatally treated w ith antidepressant drugs. It is, however, not clear what the relation is with the functional changes in these rats, that are proposed by som e authors as an animal model for depression. Copyright (C) 1996 Elsevi er Science Inc.