Reversal learning and RNA labeling in neurological mutant mice and normal littermates

Abstract

Incorporation of radioactive uridine into five brain areas, following reversal learning, was explored for neurological mutant mice with a deficit of myelin in the brain and spinal cord (quaking, qkqk) and normal littermates (?/+) from strain C57BL/6-qk (Jackson Laboratory). Both groups mastered the reversal task, although the mutants performed at a lower level. There was a Genotype × Test Conditions × Brain Area interaction with littermates exhibiting increased labeling of RNA in the amygdala and the hippocampus, and the quaking mice exhibiting no significant changes in these two areas following learning. Findings suggest that a genetic defect in the integrity of the CNS, a deficiency of myelin, affects reversal learning, and that this effect may be reflected in changes in RNA synthesis, or specific activity, for structures which are critical to reversal learning ability.