THE ROLE OF THE STRIATE DOPAMINERGIC SYST EM IN CATALEPSY REGULATION IN RATS AND MICE 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 stoc k bred for predisposition to catalepsy in the course of 21-22 generati ons), No significant differences in the content of dopamine and its ma in metabolites - 3,4-dihydroxyphenylacetic acid and homovanillic acids - were found in the striatum of CBA mice and GC rats in comparison wi th other groups. In catalepsy-predisposed animals changes were observe d only in sensitivity of dopamine receptors. After apomorphine injecti on the sensitivity of postsynaptic dopamine receptors in CBA mice was decreased (tested by stereotypic climbing). The sensitivity of both pr e-and postsynaptic receptors to injected apomorphine and haloperidol w as increased in GC rats, Thus, the observed changes in dopaminergic sy stem were not substantial and not of the same direction in rats and mi ce. It is suggested that the striate dopaminergic system does not play a key role in the mechanisms of genetic predisposition to catalepsy.