22 March 2023 - - Bioelectronic medicine researchers at The Feinstein Institutes for Medical Research have developed a new method for studying neural signals transmitted to the brain through the vagus nerve the nerve that helps controls functions like heart rate, breathing and immune response.

By using calcium imaging technology to monitor neural activity from a cluster of neurons near the base of the skull, scientists hope to discover new clues about how the body communicates with the brain.

In a new paper titled "Calcium imaging and analysis of the jugular-nodose ganglia enables identification of distinct vagal sensory neuron subsets," published in the Journal of Neural Engineering, investigators focused their attention on sensory neurons of the peripheral nervous system.

They wanted to know how these neurons encode and interpret different stimuli in the form of neural activity.

The researchers used imaging of the intact jugular-nodose ganglion which contains the sensory neurons of the vagus nerve to directly record neural activity in mice with genetically-encoded calcium indicators.

They then analyzed the signals and used a machine learning algorithm to classify the neuronal responses to different types of chemical stimuli applied to the vagus nerve.

They found that specific neuronal responses were closely associated with certain types of stimuli, reflecting an encoding of information within the PNS, before further transmission to the brain.

Led by Eric H. Chang, PhD, and postdoctoral researcher Tomás S. Huerta, PhD, the study is part of a multi-year USD 1.3m grant from the National Institutes of Health to examine how immune signals are transmitted to the brain through the vagus nerve.

The vagus nerve is often referred to as the body's superhighway it connects the brain with all major organs, and controls functions like heart rate, breathing and gastrointestinal function. When the nerve is stimulated, it can reduce inflammation, which is a trigger for many diseases, and help the body's immune system.

Inflammation is an important immune response, however if uncontrolled, can lead to serious conditions such as Crohn's disease, rheumatoid arthritis and other chronic inflammatory disorders.

In this new study, Feinstein Institutes' bioelectronic medicine researchers look at how sensory neurons encode and transmit these important physiological signals in the form of neural activity.

This information can be used for future research to develop new bioelectronic medicine devices, like vagus nerve stimulators, and better advance our methods to control the signals between the brain and body.

The Feinstein Institutes for Medical Research is a global scientific home of bioelectronic medicine, which combines molecular medicine, neuroscience and biomedical engineering.