Weekly volumes reaching or exceeding 180 min appear to provide sufficient stimulus to activate neuroprotective cascades, including hippocampal volumetric expansion, elevated BDNF [87,89,91], suppression of chronic neuroinflammation and oxidative stress [82], and pronounced dopaminergic modulation [65,66], ultimately culminating in diminished depressive symptomatology in PD. This evidence concerns the gene BDNF and Parkinson disease.