Genetic and activity-dependent regulation of Zif268 expression: Association with spatial learning

We have reported that C57BL/6 and DBA/2 mice differ in spatial learning performance and associated hippocampal protein kinase C (PKC) activity (Upchurch and Wehner, 1989, Behav Neurosci 103:1251–1258; Wehner et al., 1990, Brain Res 523:181–187) and that physical activity enhances spatial learning with related alterations in protein kinase C (PKC) (Fordyee and Wehner, 1993b, Brain Res 619:111–119). To assess whether physical activity induces alterations in gene expression that may underlie these changes in PKC and learning performance, we examined the effect of physical activity on expression of zif268, a transcription regulatory factor linked to stimulus‐induced neuronal plasticity. C57 and DBA mice, 3 months of age, were subjected to acute (one bout) or chronic (8 weeks) physical activity. The mice were then tested on the Morris water maze task for 6 days with subsequent analysis of PKC activity and zif268 mRNA expression. Control DBA mice, which have poor hippocampal‐specific learning performance compared to C57 mice (Wehner et al., 1990, Brain Res 523:181–187; Fordyce and Wehner, 1993b, Brain Res 619:111–119; Paylor et al., 1993, Psychobiology 27:11–26), displayed lower basal levels of zif268 mRNA (P