The gut-brain dopamine axis: a regulatory system for caloric intake

Area of Science:

• Neuroscience
• Physiology
• Behavioral Science

Background:

• Post-ingestive factors significantly influence feeding behavior by signaling the organism's physiological state to the central nervous system.
• Understanding the neural pathways for sensing these post-ingestive signals is crucial for comprehending appetite regulation.

Purpose of the Study:

• To review evidence on how the brain senses post-ingestive signals.
• To explore the role of dopamine in mediating the relationship between gut nutrient sensing and feeding behavior.

Main Methods:

• Review of recent scientific evidence.
• Analysis of studies involving direct gastrointestinal tract stimulation with nutrients.
• Examination of dopamine efflux changes in response to nutrient infusion and blockade of dopamine signaling.

Main Results:

• Direct gastrointestinal nutrient stimulation induces the release of the neurotransmitter dopamine.
• Dopamine efflux changes correlate with the caloric load of nutrients, suggesting a role as a central caloric sensor.
• Dopamine signaling blockade impairs flavor-nutrient associations and the regulation of caloric intake during intragastric feeding.

Conclusions:

• Dopamine signaling is implicated in sensing nutrient intake and regulating feeding behavior.
• Dopamine systems may act as a convergence site for pre- and post-absorptive signals influencing ingestive behaviors.
• Further research is needed to elucidate the precise pathways linking gut nutrient sensing to central dopamine release.