Genetic control of apomorphine-induced climbing behavior in two inbred mouse strains

Over a wide dose range (1-32 mg/kg), apomorphine-induced climbing behavior was significantly greater in the AKR/J than in the DBA/2J inbred mouse strain. A similar difference was found when apomorphine-induced stereotypy was examined. A cross-fostering study demonstrated that the strain difference in apomorphine-induced climbing behavior did not result from differences in post-natal rearing environment. After apomorphine administration, brain levels of the drug were similar in the two strains indicating that the difference in behavioral response to apomorphine in the two strains was not due to differences in metabolism or distribution of the drug. The climbing response to apomorphine was examined in the F1 cross of the two strains (AKD2F1/J) and in 10 AKXD recombinant inbred strains. Results suggested that the trait was partially dominant and not X-linked; furthermore, a few and possibly one locus was responsible for the differences in apomorphine-induced climbing behavior observed in the AKR/J and DBA/2J mice.