Thiopental, phenobarbital, and chlordiazepoxide induce the same differences in narcotic reaction as ethanol in long-sleep and short-sleep selectively-bred mice.

Hypnotic effects following administration of thiopental, phenobarbital or chlordiazepoxide were evaluated in mice selectively-bred for differential hypnotic sensitivity to ethanol. For every dose employed, except one which had no effect, all three agents induced greater sedation in the ethanol-sensitive Long-Sleep (LS) line than in the ethanol-insensitive Short-Sleep (SS) line. Such findings with regard to the LS and SS lines suggest that the differences in sedative response to ethanol, as well as some barbiturates and benzodiazepines, may be mediated, in part, by a common mechanism. The second experiment showed that age of the subjects can be an important variable influencing hypnotic-induced sleep time. For thiopental, significant line differences occurred only with 150 day old mice, whereas chlordiazepoxide produced differences in 50, 75, 100 and 150 day old mice.