Vagal Sensory Gut-Brain Pathways That Control Eating-Satiety and Beyond

Area of Science:

• Neuroscience
• Gastroenterology
• Metabolism

Background:

• The vagus nerve is a key gut-brain communication pathway.
• Traditionally, vagal afferent neurons (VANs) were considered passive satiety signal relays.
• Emerging research indicates a more active and complex role for VANs.

Purpose of the Study:

• To challenge the traditional view of VANs as simple satiety sensors.
• To highlight the diverse roles of VANs in encoding meal-related information.
• To provide a comprehensive update on vagal sensory pathways and their integrative functions.

Main Methods:

• Review of recent advances in single-cell transcriptomics.
• Integration of neural circuit mapping data.
• Synthesis of functional imaging studies.

Main Results:

• VANs actively encode mechanical stretch, nutrient content, metabolic state, and microbial metabolites.
• Specialized subpopulations of VANs possess diverse sensory modalities.
• Downstream brain circuits modulated by VANs influence feeding behavior, metabolism, and cognition.

Conclusions:

• VANs are active integrators of diverse meal information, not just passive satiety sensors.
• VANs play crucial roles beyond satiety, including in food reward and memory.
• Understanding VANs offers new insights into gut-brain communication and metabolic regulation.