Plate Nº 90 · recorded October 10, 2026
Neuroscience & MindReported finding
Stimulating the Vagus Nerve After Practice Helps Skills Stick in Mice
Mice given vagus nerve stimulation after training, not during it, showed stronger long-term learning, with effects tied to rhythmic blood volume changes in the cerebellum.
By Elena Vasquez3 min read691 words
In brief
- The study was published in iScience on August 25, 2026, by researchers at Tohoku University.
- Vagus nerve stimulation applied only after training improved long-term motor learning in mice, with benefits visible on following days and by Day 5.
- Repeated stimulation produced rhythmic oscillations in blood volume near the cerebellar flocculus.
- Mice with larger blood volume oscillations generally showed better learning.
- VNS is already clinically approved for treating several disorders.
Mice that received vagus nerve stimulation after each training session showed stronger long-term motor learning than unstimulated animals, according to a study published in iScience on August 25, 2026. The stimulation did nothing during practice itself — the benefit appeared on later days, pointing to a hidden window after training when the brain locks in a new skill.
Researchers at Tohoku University who study what they call super network brain physiology carried out the work. They found the effect was linked to rhythmic changes in blood vessels inside the brain, hinting that signals traveling from the body to the brain may help prepare the brain for lasting change.
What Is the Vagus Nerve?
The vagus nerve is one of the nervous system's major communication highways. It carries signals from internal organs to the brain and transmits instructions back the other way. Clinicians can influence this pathway using vagus nerve stimulation (VNS), a technique already approved for treating several disorders.
Earlier research treated VNS mainly as a form of neuromodulation — a way of changing activity in neurotransmitter systems, the brain's chemical messengers. The new study suggests a second mechanism may matter: rhythmic changes in blood vessels inside the brain.
How Did the Researchers Test It?
The team, led by Professor Ko Matsui and lead author Junyu Chen, built a small cuff electrode designed to stay attached to the left cervical vagus nerve in mice. They then tested VNS during a task called horizontal optokinetic response (HOKR) learning — a cerebellum-dependent eye movement exercise in which mice learn to better follow moving visual stripes.
The response resembles the automatic eye movements a person makes while standing on a platform watching a train pass. The cerebellum, a region at the back of the brain that controls coordination, drives the learning.
The critical design choice was timing. The researchers applied stimulation only after each training session, not while the mice were performing the task.
Why Does Timing Matter?
The stimulation produced no immediate improvement while the mice trained. Instead, benefits emerged later: on following days, mice that received VNS showed stronger long-term learning.
This pattern suggests VNS may act on consolidation — the process by which the brain converts what it has just practiced into durable memory.
"The key point is that VNS was delivered only after training," Professor Matsui said. "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."
What Happened in the Brain's Blood Vessels?
The team next searched for brain changes that might accompany the improved learning. Using fiber photometry — a method that measures brain activity through light-sensitive fibers — they tracked blood volume near the cerebellar flocculus, an area involved in HOKR learning.
A single round of VNS produced a two-phase vascular response: local blood volume briefly decreased, then rose after a delay. When the researchers repeated the stimulation, it created rhythmic oscillations in blood volume.
Those rhythms tracked with learning. Mice with larger blood volume oscillations generally performed better by Day 5, suggesting that changes in the brain's vascular environment could underlie the longer-lasting effects of the stimulation.
"Our brains may be more strongly influenced by the body than we imagine," lead author Junyu Chen said. "By tuning the brain's metabolic environment, including rhythmic vascular movements, we may eventually unlock capacities that would otherwise remain latent."
What Are the Limits?
These results come from mice, and the findings are preliminary. The study does not show that post-training VNS would enhance human skill learning, and the link between vascular rhythms and learning is a correlation observed in the animals, not a proven cause.
Future research will focus on refining stimulation protocols and determining more precisely how brain-body communication supports long-term plasticity — the brain's ability to rewire itself. By studying this two-way pathway in detail, the researchers hope to understand how learning becomes lasting, and how that process might eventually be enhanced.
The paper, by Junyu U. Chen, Yoko Ikoma and Ko Matsui, appears in iScience (2026, vol. 29, issue 9, article 117413).
via dx.doi.org (Original)
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