An inter-organ neural circuit for appetite suppression.

Area of Science:

• Neuroscience
• Gastroenterology
• Endocrinology

Background:

• Glucagon-like peptide-1 (GLP-1) is an intestinal hormone with known effects on appetite and gut motility.
• The precise mechanisms by which intestinal GLP-1 influences distant organs, especially given its rapid inactivation, remain largely unclear.

Purpose of the Study:

• To elucidate the neural pathways through which intestinal GLP-1 exerts its effects on gastric function and eating behavior.
• To investigate the role of intestinofugal neurons in mediating GLP-1's actions.

Main Methods:

• Utilized cell-specific ablation and chemical activation of intestinofugal neurons in animal models.
• Traced neural pathways involved in GLP-1 signaling from the gut to the central nervous system.

Main Results:

• Intestinal GLP-1 inhibits gastric emptying and eating by activating intestinofugal neurons.
• Ablation of these neurons abolished GLP-1's effects, while their activation mimicked GLP-1.
• Identified a sympatho-gastro-spinal-reticular-hypothalamic pathway mediating these actions.

Conclusions:

• Intestinofugal neurons are critical mediators of intestinal GLP-1's effects on gastric motility and appetite.
• These findings reveal a novel neural circuit linking gut hormone signaling to central feeding and rejection behaviors.
• Targeting these enteric circuits could provide new treatments for disorders characterized by abnormal gastric motility, bloating, and appetite loss.