Use of Repeated Measures in an Analysis of Ethanol-Induced Loss of Righting Reflex in Inbred Long-Sleep and Short-Sleep Mice

Authors

  • Paul D. Markel,

    1. Institute for Behavioral Genetics, University of Colorado, Boulder, Colorado.
    2. Department of Psychology, University of Colorado, Boulder, Colorado.
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  • John C. DeFries,

    1. Institute for Behavioral Genetics, University of Colorado, Boulder, Colorado.
    2. Department of Psychology, University of Colorado, Boulder, Colorado.
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  • Thomas E. Johnson

    Corresponding author
    1. Institute for Behavioral Genetics, University of Colorado, Boulder, Colorado.
    2. Department of Psychology, University of Colorado, Boulder, Colorado.
    3. Department of Veterans Affairs Medical Center, Denver, Colorado.
      Thomas E. Johnson, Ph.D., Institute for Behavioral Genetics, University of Colorado, CB 447, Boulder, CO 80309–0447.
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  • This study was supported by the National Institute on Alcohol Abuse and Alcoholism (Grants AA03527 and AA08940), by the Denver Veteran's Administration Research Center (to T.E.J.), and by a training grant from the National Institute of Mental Health (Grant MH-16880 to P.D.M.).

Thomas E. Johnson, Ph.D., Institute for Behavioral Genetics, University of Colorado, CB 447, Boulder, CO 80309–0447.

Abstract

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 F1 and F2 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, mice, but is highly significant (0.47, p < 0.01) in the F2 mice. Mean LRR does not differ between trials 1 and 2, with the exception of the ISS strain in which the interaction of sex 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.

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