Kristen Sparrow • October 02, 2021
This is an abstract from the recent Bioelectronic summit. I am keeping tabs on all of the cytokines and mechanisms because they, in many instances, can explain how acupuncture works. I realize this is can seem abstract, but with enough data coming in, we will have a fuller picture. Building the science brick by bridk.
Sensory vagus nerve fibers transmit information in the form of action potentials to the central nervous system to maintain immunological homeostasis. Pro-inflammatory molecules including LPS, TNF, and IL-1β induce cytokine specific electrophysiological changes in vagus nerve signaling. In addition, these pro-inflammatory molecules directly activate nodose ganglion neurons, the location of sensory vagus nerve cell bodies. Previous studies have shown cytokines have a direct impact on cation channels TRPV1 and TRPA1, which are expressed on sensory fibers of the vagus nerve. Reasoning that these cation channels may play a role in vagus nerve mediated cytokine signaling we explored TRPA1’s role in IL-1β induced vagus nerve activity. Extra neural electrical activity was recorded from the cervical vagus nerve in response to i.p. administration of IL-1β. IL-1β induces a significant increase in vagus nerve activity in wild type mice, however this response was ablated in whole body TRPA1 KO mice as well as neuronal specific TRPA1 KO mice (SynCre-TRPA1flox). Using calcium imaging and whole cell patch clamp recordings, we observed nodose ganglion neurons deficient in TRPA1 do not respond to IL-1β application. In addition, IL-1β induced calcium influx was inhibited by administration of the TRPA1 antagonist AM0902. These results elucidate a novel role for the TRPA1 cation channel as a necessary component for IL-1β induced vagus nerve signaling.