The MouseFlex electrode created by WVU researchers will advance testing of vagus nerve stimulation, a cutting-edge bioelectronic treatment for conditions that range from epilepsy to arthritis to hypertension. Here Justin Vankirk, a doctoral candidate in mechanical and aerospace engineering, releases microfabricated MouseFlex electrodes from a silicon wafer and solder-integrates leads to the device for electrochemical testing. (WVU Photo/Paige Nesbit)

Engineers are taking a major step into “bioelectronic medicine,” a cutting-edge approach that uses electric current as a treatment for pain and disease, with the development of MouseFlex. The device will facilitate research into a technique called vagus nerve stimulation or VNS.

The vagus nerve is responsible for involuntary body functions such as heart rate, breathing and digestion. Because VNS trials on mice must happen before new bioelectronic treatments can be tested on humans, the MouseFlex — a tiny electrode that has been formed into a cuff shape, like the cuff of a shirt sleeve — fits around the vagus nerve of a mouse and delivers electrical impulses.

According to its developers, the MouseFlex outperforms existing technology when it comes to withstanding both the electric current flowing through it and the handling it sustains during the course of surgery.

Due to the small size of both the mouse vagus nerve and the electrodes, it has been challenging to interface with the nerve and challenging for the electrodes to remain stable throughout the process of electrical stimulation.

Roughly 125,000 people around the world have VNS stimulators for epilepsy or depression. However, a new condition being evaluated for VNS treatment is rheumatoid arthritis, an autoimmune condition in which the immune system attacks the body’s joints. Additional conditions for which VNS using flexible electrodes like the MouseFlex shows promise: depression, obesity, and high blood pressure, also known as hypertension.