Gastric neurons in the nucleus tractus solitarius are selective to the orientation of gastric electrical stimulation
Year: 2021
Type: article
Abstract: Gastric electrical stimulation (GES) is a bioelectric intervention for gastroparesis, obesity, and other functional gastrointestinal disorders. In a potential mechanism of action, GES activates the nerve endings of vagal afferent neurons and induces the vago-vagal reflex through the nucleus tractus solitarius (NTS) in the brainstem. However, it is unclear where and how to stimulate in order to optimize the vagal afferent responses. To address this question with electrophysiology in rats, we applied mild electrical currents to two serosal targets on the distal forestomach with dense distributions of vagal intramuscular arrays that innervated the circular and longitudinal smooth muscle layers. During stimulation, we recorded single and multi-unit responses from gastric neurons in NTS and evaluated how the recorded responses depended on the stimulus orientation and amplitude. We found that NTS responses were highly selective to the stimulus orientation for a range of stimulus amplitudes. The strongest responses were observed when the applied current flowed in the same direction as the intramuscular arrays in parallel with the underlying smooth muscle fibers. Our results suggest that gastric neurons in NTS may encode the orientation-specific activity of gastric smooth muscles relayed by vagal afferent neurons. This finding suggests that the orientation of GES is critical to effective engagement of vagal afferents and should be considered in light of the structural phenotypes of vagal terminals in the stomach.
Source: Journal of Neural Engineering
Institutions: University of Michigan, Purdue University West Lafayette
Language: English
Subfield: Gastroenterology
Field: Medicine
Domain: Health Sciences
Open Access status: green
Awards: Mapping Stomach Autonomic Circuitry and Function for Neuromodulation of Gastric Disorders, University of Michigan Center for Gastrointestinal Research, Autonomic Control of Body Weight and Feeding, The Virtual Stomach, Use of novel MRI technology to study pathophysiology diabetic gastroparesis, Functional Neural Circuits of Stomach-Brain Interoception, G984930731
OpenAlex ID: W3205863227