Post-Training Vagus Nerve Stimulation Strengthens Long-Term Motor Learning in Mice via Cerebellar Blood Volume Oscillations

The team implanted cuff electrodes on the left cervical vagus nerve in mice and applied stimulation only after each HOKR training block. Performance during sessions remained unchanged, yet retention improved markedly by day 5, indicating effects on consolidation rather than acquisition. Fiber photometry revealed a two-phase vascular response—brief blood volume drop followed by delayed rise—that became oscillatory with repeated stimulation and correlated with learning magnitude.

This vascular mechanism extends prior VNS work focused on neurotransmitter modulation, such as human epilepsy trials showing memory benefits. The original coverage underplays how body-to-brain signaling could interact with metabolic clearance during offline periods, a gap also seen in stroke recovery studies where timing of stimulation proved critical. Animal-only data leaves open whether similar rhythms occur in human cerebellum during skill practice.

Next steps include protocol optimization for non-invasive delivery and targeted human trials in motor rehabilitation, testing whether post-practice VNS windows yield measurable retention gains beyond standard training.