Exercise induces hypothalamic cell proliferation in mice

(HealthDay)—Exercise training induces hypothalamic cell proliferation in adult mice and improves insulin sensitivity, but blocking cell proliferation does not prevent insulin action, according to an experimental study published online June 4 in Diabetes.

Melissa L. Borg, from Monash University in Australia, and colleagues examined whether exercise training causes hypothalamic neurogenesis in a study conducted in adult mice. They also assessed whether the hypothalamic neurogenesis contributes to exercise-induced improvements in insulin action.

The researchers found that acute exercise induced a pro-neurogenic transcriptional program, which involved growth factors, cell proliferation, and neurogenic regulators in the hypothalamus. Hypothalamic cell proliferation was increased 3.5-fold with daily exercise training for seven days, compared with sedentary mice, and this cell proliferation was maintained in diet-induced obese mice. Sedentary and exercise-trained mice had negligible neurogenesis in the hypothalamic arcuate nucleus. Neither food intake nor body mass was affected by blocking cell proliferation via administration of the mitotic blocker cystosine-1-β-D-arabinofuranoside (AraC). Whole-body insulin sensitivity was improved with four weeks of exercise training versus sedentary mice, but AraC administration did not affect insulin action.

"These data suggest that regular exercise training induces significant non-neuronal cell proliferation in the hypothalamus of obese mice, but this proliferation is not required for enhanced insulin action," the authors write.