Acute effects of aerobic exercise on corticomotor plasticity in individuals with and without depression

Although complex in nature, the pathophysiology of depression involves reduced or impaired neuroplastic capabilities. Restoring or enhancing neuroplasticity may serve as a treatment target for developing therapies for depression. Aerobic exercise (AEx) has antidepressant benefits and may enhance neuroplasticity in depression although the latter has yet to be substantiated. Therefore, we sought to examine the acute effect of AEx on neuroplasticity in depression.

Sixteen individuals with (DEP; 13 female; age = 28.5 ± 7.3; Montgomery-Äsberg Depression Rating Scale [MADRS] = 21.3 ± 5.2) and without depression (HC; 13 female; age 27.2 ± 7.5; MADRS = 0.8 ± 1.2) completed three experimental visits consisting of 15 min of low intensity AEx (LO) at 35% heart rate reserve (HRR), high intensity AEx (HI) at 70% HRR, or sitting (CON). Following AEx, excitatory paired associative stimulation (PAS_25ms) was employed to probe neuroplasticity. Motor evoked potentials (MEP) were assessed via transcranial magnetic stimulation before and after PAS_25ms to indicate acute changes in neuroplasticity.

PAS_25ms primed with HI AEx led to significant increases in MEP amplitude compared to LO and CON. HI AEx elicited enhanced PAS_25ms-induced neuroplasticity for up to 1-h post-PAS. There were no significant between-group differences.

HI AEx enhances PAS measured neuroplasticity in individuals with and without depression. HI AEx may have a potent influence on the brain and serve as an effective primer, or adjunct, to therapies that seek to harness neuroplasticity.