regarding the 2010 study, the authors conclude: "we also demonstrate that increased hippocampal volume is associated with greater serum levels of bdnf, a mediator of neurogenesis in the dentate gyrus. hippocampal volume declined in the control group, but higher preintervention fitness partially attenuated the decline, suggesting that fitness protects against volume loss. caudate nucleus and thalamus volumes were unaffected by the intervention. these theoretically important findings indicate that aerobic exercise training is effective at reversing hippocampal volume loss in late adulthood, which is accompanied by improved memory function."