Voluntary running improves depressive behaviours and the structure of the hippocampus in rats: A possible impact of myokines

•Voluntary running produced significant changes in the depressive behaviours.•Voluntary running produced evident changes in the structure of hippocampal formation.•Voluntary running produced significant changes in the myokine levels.•A significant correlation was detected between BDNF levels of and other myokines.•A possible different response of regions of dentate gyrus to voluntary running.