Transcutaneous auricular vagus nerve stimulation induces an antidepressant effect by activating the dopaminergic neurons in the ventral tegmental area

초록

Depression, a prevalent neuropsychiatric disorder, involves the dysregulation of neurotransmitters such as dopamine (DA). The restoration of DA balance is a pivotal therapeutic target for this condition. Recent studies have indicated that both antidepressant medications and non-pharmacological treatments, such as transcutaneous auricular vagus nerve stimulation (taVNS), can promote recovery from depressive symptoms. Despite the promise of taVNS as a non-invasive depression therapy, its precise mechanism remains unclear. We postulated that taVNS elicits antidepressant effects by affecting the DAergic system. To address this, we conducted experiments which demonstrated that taVNS reduced depressive-like behavior, which were abolished when DA neurons in the ventral tegmental area (VTADA) was inhibited. Additionally, taVNS enhanced VTADA activity, providing further evidence to support its antidepressant effects. Overall, our findings suggest that taVNS alleviates depression by augmenting VTADA activity, thereby contributing to a more comprehensive understanding of its therapeutic mechanisms.