Test- and behavior-specific genetic factors affect WKY hypoactivity in tests of emotionality

Behav Brain Res. 2006 May 15;169(2):220-30. doi: 10.1016/j.bbr.2006.01.007. Epub 2006 Feb 20.


Inbred Wistar-Kyoto rats consistently display hypoactivity in tests of emotional behavior. We used them to test the hypothesis that the genetic factors underlying the behavioral decision-making process will vary in different environmental contexts. The contexts used were the open-field test (OFT), a novel environment with no explicit threats present, and the defensive-burying test (DB), a habituated environment into which a threat has been introduced. Rearing, a voluntary behavior was measured in both tests, and our study was the first to look for genetic loci affecting grooming, a relatively automatic, stress-responsive stereotyped behavior. Quantitative trait locus analysis was performed on a population of 486 F2 animals bred from reciprocal inter-crosses. The genetic architectures of DB and OFT rearing, and of DB and OFT grooming, were compared. There were no common loci affecting grooming behavior in both tests. These different contexts produced the stereotyped behavior via different pathways, and genetic factors seem to influence the decision-making pathways and not the expression of the behavior. Three loci were found that affected rearing behavior in both tests. However, in both contexts, other loci had greater effects on the behavior. Our results imply that environmental context's effects on decision-making vary depending on the category of behavior.

Publication types

  • Comparative Study
  • Research Support, N.I.H., Extramural

MeSH terms

  • Agonistic Behavior
  • Animals
  • Behavior, Animal / physiology*
  • Crosses, Genetic
  • Decision Making / physiology*
  • Emotions / physiology*
  • Exploratory Behavior / physiology
  • Female
  • Grooming / physiology
  • Habituation, Psychophysiologic
  • Motor Activity / genetics
  • Phenotype
  • Psychomotor Performance / physiology
  • Quantitative Trait Loci
  • Rats
  • Rats, Inbred WKY / genetics*
  • Rats, Sprague-Dawley
  • Regression Analysis
  • Sex Factors
  • Social Environment