[The participation of the dopaminergic system of the striatum in the regulation of catalepsy in mice and rats of different genotypes].

Dopaminergic striate system was studied in mice of six inbred strains (AKR, BALB/c, DD, CC57BR, C57BL/6, and CBA--the last with hereditary predisposition to catalepsy) and Wistar rats (normal stock and GC stock bred for predisposition to catalepsy in the course of 21-22 generations). No significant differences in the content of dopamine and its main metabolites--3,4-dihydroxyphenylacetic acid and homovanillic acids--were found in the striatum of CBA mice and GC rats in comparison with other groups. In catalepsy-predisposed animals changes were observed only in sensitivity of dopamine receptors. After apomorphine injection the sensitivity of postsynaptic dopamine receptors in CBA mice was decreased (tested by stereotypic climbing). The sensitivity of both pre- and postsynaptic receptors to injected apomorphine and haloperidol was increased in GC rats. Thus, the observed changes in dopaminergic system were not substantial and not of the same direction in rats and mice. It is suggested that the striate dopaminergic system does not play a key role in the mechanisms of genetic predisposition to catalepsy.