Swallowed magnetoelectric particles stimulate the vagus nerve from the stomach in mouse models of Parkinson's

What happened

Vagus nerve stimulation has shown neuroprotective and anti-inflammatory effects in Parkinson's disease, but it normally requires an implanted device. The researchers made particles with a magnetically responsive nickel ferrite core and a piezoelectric barium titanate shell, coated with capsaicin so that they bind TRPV1 receptors and stick to the stomach lining after being swallowed.

When a magnetic field is applied, the particles generate electrical pulses that activate vagal afferent fibres, which signal to the nucleus tractus solitarius in the brainstem. The authors report that this increased norepinephrine production in the locus coeruleus and dopamine synthesis in the substantia nigra, and that vagal efferent activation triggered the cholinergic anti-inflammatory pathway, reducing both brain and systemic inflammation. Therapeutic effects were tested in two mouse models of Parkinson's disease, induced with MPTP and with DSP4. The authors say the approach shows potential for alleviating motor symptoms and anxiety.

Why it matters

Conventional vagus nerve stimulation is invasive and carries procedural and device-related risks. Reaching the nerve's endings in the gut with a swallowed material and an external magnetic field is a different way in, and could lower the barrier to trying vagal stimulation in neurodegenerative disease.

Caveats

This entry is based on the abstract and the figure titles on the journal's page; the full text is behind a paywall and was not read. The abstract gives no numerical results. The work is in mice, and no human testing is reported. The authors declare no competing interests.