Involvement of dopaminergic processes in the striatum during the effects of corticoliberin on the behavior of active and passive rats.

The effects of intranasal corticoliberin on behavior in the open field test were studied in rats with active and passive behavioral strategies (lines KHA and KLA); levels of dopamine and noradrenaline and their metabolites were measured in the striatum and hypothalamus. In KLA rats, administration of the neurohormone led to increases in motor and investigative activity, while decreases were seen in KHA rats. There were no interline differences in catecholamine levels in the hypothalamus, while dopamine levels in the KLA striatum nearly doubled and metabolite levels (DOPAC, HVA) were significantly lower than in KHA rats. Corticoliberin increased dopamine and noradrenaline levels in the hypothalamus of both rat lines, with significant decreases in the striatum. This decrease was more marked in KLA rats, probably due to the faster metabolism of transmitters in the presence of neurohormones, as indicated by the increase in metabolite levels in this structure.