BDNF Haploinsufficiency Limits Voluntary Exercise-Induced Adult Hippocampal Neurogenesis

Abstract

Simple Summary Regular exercise boosts the brain’s ability to generate new nerve cells in the postnatal hippocampus, a region which is important for learning and memory. Here, we analyzed whether a protein, called brain-derived neurotrophic factor, is needed for this effect. We studied six-month-old male mice with only one working copy of the brain-derived neurotrophic factor gene and compared them to normal mice, with or without access to a running wheel. Mice with the less brain-derived neurotrophic factor weighed a bit more and ran slightly differently. Without exercise, both groups showed similar numbers of new hippocampal cells. When given a running wheel, both groups increased the production of new neurons, but the increase was smaller in the mice with the reduced brain-derived neurotrophic factor. This suggests normal brain-derived neurotrophic factor levels are not required for maintaining baseline cell production, but brain-derived neurotrophic factor is important for the additional increase that comes from physical activity.