BDNF and early-onset autosomal dominant Alzheimer disease: Furthermore, exercise promotes neuroplasticity and synaptic function in the hippocampus and prefrontal cortex by increasing the levels of brain-derived neurotrophic factor (BDNF) and insulin-like growth factor (IGF-1) (56, 57), which are correlated with increased hippocampal volume and increased BDNF and BDNF release in Alzheimer’s disease patients.