Immediate glucose signaling transmitted via the vagus nerve in gut–brain neural communication

Sucrose consumption is influenced by certain gut-brain signaling mechanisms. One possible pathway could be the interaction between the vagus nerve and the central nervous system, mediated by neuropod cells forming synaptic connections with vagus nerves, which immediately activate the central dopaminergic pathways. In this study, we demonstrated that intestinal glucose administration activates the frontal cortex via the vagus nerve and central dopamine signaling. The immediate activation of both the vagus nerve and the frontal cortex was mediated by the sodium-glucose cotransporter 1 (SGLT1). Furthermore, Ca²⁺ signal activation in both astrocytes and neurons in the frontal cortex was mediated by D2 and D1 receptors, respectively. Finally, we showed that psychological stress, which causes a sucrose preference reduction, significantly diminished the activation levels of both the vagus nerve and the frontal cortex. These findings highlight the role of a comprehensive gut-brain network via vagus nerves in modulating sucrose preference.