USE OF REPEATED-MEASURES IN AN ANALYSIS OF ETHANOL-INDUCED LOSS OF RIGHTING REFLEX IN INBRED LONG-SLEEP AND SHORT-SLEEP MICE

We present a repeated-measures analysis of ethanol-induced loss of righting reflex (LRR) in Inbred Long-Sleep (ILS) and Inbred Short Sleep (ISS) strains of mice and their F-1 and F-2 cross progeny. Mice were administered a 4.1 g/kg intraperitoneal dose of ethanol at two times, 7-10 days apart, Repeatability is nonsignificant in ILS, ISS, and F-1 mice, but is highly significant (0.47, p < 0.01) in the F-2 mice. Mean LRR does not differ between trials 1 and 2, with the exception of the ISS strain in which the interaction of sei with LRR sensitization is significant. This two-trial method leads to increased accuracy of genotype assessment for pharmacological or behavioral traits where trial 1 does not influence the outcome of trial 2. The repeated measures design facilitates novel analyses of the duration of LRR, and results suggest that most environmental variance for LRR is due to nonreplicable influences.