Vagus Nerve Stimulation Boosts Motor Learning in Mice

Learning may depend on more than just the brain. Signals from internal organs travel to the brain through the vagus nerve, a major communication pathway in the nervous system. A study led by researchers at Tohoku University now suggests that stimulating this nerve after practice can help motor skills stick.

The findings were published in iScience on August 25, 2026.

The Vagus Nerve and Learning

The vagus nerve is a two-way highway between the brain and the body. It carries information from organs up to the brain and sends instructions back down. Scientists can influence this pathway with vagus nerve stimulation (VNS), a technique already approved for treating several disorders.

Previous research has mostly looked at VNS as a way to change neurotransmitter activity. The new study points to another possible mechanism: rhythmic changes in blood vessels inside the brain.

To test this, the researchers built a small cuff electrode that stayed attached to the left cervical vagus nerve in mice. They then measured the effect of VNS on a cerebellum-dependent eye movement task. In the task, mice learned to follow moving vertical stripes. The response is similar to the automatic eye movements a person makes while standing on a platform and watching a train pass.

The Biggest Effect Appeared After Practice

VNS was applied after each training session, not during the task itself. The stimulation did not improve performance while the mice trained. Instead, the benefits showed up later.

On following days, mice that received VNS showed stronger long-term learning. The pattern suggests the stimulation may affect processes that happen after training, when the brain consolidates what it has learned into more durable memory.

"The key point is that VNS was delivered only after training," said Professor Ko Matsui in a statement reported by ScienceDaily. "Our findings suggest that VNS may open a hidden window of opportunity for enhanced learning by making the brain environment more receptive to long-lasting change."

Rhythmic Changes in Brain Blood Volume

The team then looked for changes inside the brain that might accompany the improved learning. They measured blood volume activity near the cerebellar flocculus, an area involved in the eye movement task.

Using fiber photometry, the researchers found that a single round of VNS produced a two-phase vascular response. Local blood volume briefly decreased before rising after a delay. When VNS was repeated, it created rhythmic oscillations in blood volume.

These vascular rhythms appeared linked to learning. Mice with larger blood volume oscillations generally showed better learning by Day 5, suggesting a connection between the brain's vascular environment and the longer-lasting effects of stimulation.

"Our brains may be more strongly influenced by the body than we imagine," said lead author Junyu Chen, as reported by ScienceDaily. "By tuning the brain's metabolic environment, including rhythmic vascular movements, we may eventually unlock capacities that would otherwise remain latent."

Exploring the Brain-Body Connection

Future research will focus on refining stimulation protocols and understanding how communication between the brain and body supports long-term plasticity. By studying this two-way pathway in more detail, scientists hope to learn how lasting changes in learning occur and how the process might eventually be enhanced.

• brain-body connection
• iScience
• mice
• motor learning
• Tohoku University
• vagus nerve