Vagal nerve signals help early fullness and stop dislike of flavors after injected exendin-4

Subdiaphragmatic vagal deafferentation blunted the short-term eating-inhibitory effect of Ex-4 but not the long-term effect.

• A dose of 1 μg/kg Ex-4 reduced cumulative food intake similarly in both vagally deafferented and sham-operated rats.
• Vagal deafferentation resulted in the development of conditioned flavour avoidance after Ex-4 administration, which did not occur in sham rats.
• Ex-4 induced c-Fos expression in brain regions associated with reward and stress response, independent of intact vagal afferents.
• Intact vagal afferents appear necessary for the initial satiating effect of Ex-4, while later effects may occur through circulation to the brain.
• The findings suggest a complex role of vagal afferents in regulating eating behavior and avoidance responses associated with GLP-1 receptor activation.

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