Variable impact of chronic stress on spatial learning and memory in BXD mice

Physiol Behav. 2015 Oct 15;150:69-77. doi: 10.1016/j.physbeh.2015.06.022. Epub 2015 Jun 14.

Abstract

The effects of chronic stress on learning are highly variable across individuals. This variability stems from gene-environment interactions. However, the mechanisms by which stress affects genetic predictors of learning are unclear. Thus, we aim to determine whether the genetic pathways that predict spatial memory performance are altered by previous exposure to chronic stress. Sixty-two BXD recombinant inbred strains of mice, as well as parent strains C57BL/6J and DBA/2J, were randomly assigned as behavioral control or to a chronic variable stress paradigm and then underwent behavioral testing to assess spatial memory and learning performance using the Morris water maze. Quantitative trait loci (QTL) mapping was completed for average escape latency times for both control and stress animals. Loci on chromosomes 5 and 10 were found in both control and stress environmental populations; eight additional loci were found to be unique to either the control or stress environment. In sum, results indicate that certain genetic loci predict spatial memory performance regardless of prior stress exposure, while exposure to stress also reveals unique genetic predictors of training during the memory task. Thus, we find that genetic predictors contributing to spatial learning and memory are susceptible to the presence of chronic stress.

Keywords: BXD; Genetics; QTL; Spatial learning; Spatial memory; Stress.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • Gene Regulatory Networks / genetics
  • Gene-Environment Interaction*
  • Maze Learning / physiology
  • Mice
  • Mice, Inbred C57BL
  • Mice, Inbred DBA
  • Quantitative Trait Loci
  • Rats, Transgenic
  • Spatial Learning / physiology*
  • Spatial Memory / physiology*
  • Stress, Psychological / physiopathology*