A Hybrid Biomonitoring System for Gut-Neuron Communication

This work presents an integrated electrochemical and electrophysiological biomonitoring system, enabling the study of molecular signaling along the gut-brain-axis (GBA). In vitro gut cell cultures provide a controllable, accessible platform to study gut physiology. Similarly, the ex vivo crayfish abdominal nerve cord provides a model for the electrophysiological study of nerve signaling. For the first time, our system integrates these platforms to enable the study of signaling from gut to nervous system, which in vivo would influence the brain. The platform consists of two interconnected modules: (I) the electrochemistry module (ECM), mimicking a Transwell platform for cell growth and enabling neurotransmitter (serotonin (5-HT)) detection, and (II) the electrophysiology module (EPM), hosting a dissected crayfish nerve cord and allowing electrode accessibility for the assessment of nerve responses to 5-HT. Whole system integration is aided by the inclusion of a flexible heater to maintain cells near body temperature (38° C), transwell membrane modification to improve molecular diffusion (450-fold) while maintaining good cell compatibility, and precise flow-controlled 5-HT transport from ECM to EPM. This work achieves module-specific environmental control, which will ultimately enable the study of molecular signaling between gut and nerve cells to facilitate real-time monitoring of both tissues within the GBA.