Selective breeding of mice for differential sensitivity to diazepam

A selective breeding study for differential sensitivity to diazepam was carried out from an outbred stock of Swiss albino mice. Mice were selected and mated according to their sleep times in response to a low hypnotic dose of 35 mg/kg diazepam. Only brother/sister mating was allowed for subsequent generations. Over six generations of two-way selection, it appears that upward selection for increased sleep time to diazepam was more effective, with a realized heritability of .7, compared to .3 for downward selection. It is concluded that a mouse line has been established that exhibits a relatively long sleep duration in response to diazepam administration.