[The unreliability of selecting short- and long-sleep mice by the results of a one-time determination of the duration of ethanol anesthesia].

Duration of ethanol (5 g/kg, orally) anesthesia was measured in male C57 B1/6 and white SHR (bred from Swiss) mice in three consecutive experiments with a 7-day interval between them. The number of short-sleep (SS) mice (duration of anesthesia was 30 min) and long-sleep (LS) mice (duration of anesthesia was over 120 min) in the selected groups decreased in the second and third experiments. This means that groups of SS and LS taken one and two weeks after the first selection for any experiment are not homogeneous because only in some animals the initial characteristics remain.