Treadmill exercise improves spatial learning ability by increasing cell proliferation in offspring born to maternal rats receiving stress during pregnancy

Abstract

Prenatal stress causes learning deficits by inhibiting neurogenesis in the hippocampus. We studied the effects of maternal treadmill running or offspring treadmill running on the spatial learning ability of adolescent offspring rats or adult offspring rats born to maternal rats that received stress during pregnancy. For this study, spatial learning ability was measured by radial 8-arm maze task. Immunohistochemistry for 5-bromo-2'-deoxyuridine and Western blot for brain-derived neurotrophic factor (BDNF), tyrosine kinase B (TrkB), Bcl-2-associated X protein (Bax), and B-cell lymphoma 2 (Bcl-2) were also conducted. Stress was induced by exposing pregnant rats to hound in an enclosed room. Maternal treadmill running or treadmill running of offspring improved spatial learning ability of adolescent and adult offspring rats born to maternal rats receiving stress during pregnancy. Maternal treadmill running or treadmill running of offspring increased hippocampal cell proliferation of adolescent and adult offspring rats born to maternal rats receiving stress during pregnancy. Maternal treadmill running or treadmill running of offspring increased BDNF and TrkB expression in the hippocampus of adolescent and adult offspring rats born to maternal rats receiving stress during pregnancy. Maternal treadmill running or treadmill running of offspring inhibited Bax expression and increased Bcl-2 expression in the hippocampus of adolescent and adult offspring rats born to maternal rats receiving stress during pregnancy. Mother's exercise during pregnancy or child's exercise after childbirth can improve the spatial learning ability deteriorated due to stress during pregnancy.

Keywords: Apoptosis; Brain-derived neurotrophic factor; Cell proliferation; Maternal stress; Spatial learning ability; Treadmill exercise.