Speaker
Description
Transcutaneous Vagus Nerve stimulation (tVNS) has been proposed as a prospective treatment for clinical conditions with altered GABAergic neurotransmission. Several studies demonstrated that tVNS can improve, at least at behavioural level, participants’ performance in inhibitory control tasks, supposedly mediated by GABA neurotransmission. However, the neurophysiological evidence showing its effects on GABA-mediated inhibition in the motor cortex is still limited. Here, we aim to investigate the effect of active (vs. sham) tVNS on corticospinal excitability and cortical inhibition as assessed through single and paired-pulse Transcranial Magnetic Stimulation.
Left-ear tVNS was delivered while participants performed a computerized visuo-motor task. In a baseline condition and after delivering tVNS, excitatory and inhibitory (GABA-A and GABA-B mediated) indices were assessed from the left (ipsilateral to tVNS) or the right (contralateral to tVNS) motor cortex.
Preliminary results revealed a facilitatory effect on visuomotor task performance during active vs. sham tVNS. Moreover, we found a specific increase after active compared to sham tVNS of intracortical inhibition mechanism mainly mediated by GABA-A receptors, either in the left or the right motor cortex. The study provides supportive evidence for the application of tVNS as an alternative, non-invasive and coadjuvant treatment for disorders featured by altered inhibitory mechanisms.
