Fat cell-secreted adiponectin mediates physical exercise-induced hippocampal neurogenesis: an alternative anti-depressive treatment?

Psychological depression is drawing accumulating attention nowadays, due to the skyrocketing incidence worldwide and the enormous burdens it incurs. Physical exercise has been long recog- nized for its therapeutic effects on depressive disorders, although knowledge of the underlying mechanisms remains limited. Suppressed hippocampal neurogenesis in adult brains has been regarded, at least partly, contributive to depression, whereas physical exercise that restores neuro- genesis accordingly exerts the anti-depressive action. Several recent publications have suggested the potential role of adiponectin, a protein hormone secreted by peripheral mature adipocytes, in mediating physical exercise-triggered enhancement of hippocampal neurogenesis and alleviation of depression. Here, we briefly review these novel findings and discuss the possibility of counter- acting depression by modulating adiponectin signaling in the hippocampus with interventions including physical exercise and administration of pharmacological agents.