A subcortical feeding circuit linking an interoceptive node to jaw movement.

Area of Science:

• Neuroscience
• Behavioral Neuroscience
• Hypothalamic Circuitry

Background:

• Understanding neural pathways for feeding behavior is crucial for addressing metabolic disorders.
• The link between interoceptive signals and feeding output remains incompletely understood.
• Brain-derived neurotrophic factor (BDNF) plays a role in neuronal function and plasticity.

Purpose of the Study:

• To delineate the specific subcortical circuit connecting interoceptive inputs to feeding behaviors.
• To investigate the role of BDNF-expressing neurons in the ventromedial hypothalamus (VMH) in regulating food consumption and jaw movements.

Main Methods:

• Investigated neural pathways using optogenetic manipulation of VMH^BDNF neurons and perimesencephalic trigeminal area (pMe5) projections.
• Monitored neuronal activity in relation to food availability, consumption, and animal obesity.
• Examined synaptic inputs from arcuate nucleus (Arc) neurons (AgRP and POMC) to VMH^BDNF neurons.

Main Results:

• A direct circuit from VMH^BDNF neurons to jaw motor centers was identified, controlling feeding.
• Inhibition of VMH^BDNF neurons increased food intake and induced consummatory behaviors towards non-food objects.
• This Arc → VMH^BDNF → pMe5 circuit senses energy state and regulates feeding behavior.

Conclusions:

• VMH^BDNF neurons are critical regulators of feeding behavior, gating motor sequences.
• This newly identified circuit integrates internal energy signals to modulate consummatory actions.
• Dysregulation of this pathway may contribute to obesity and altered feeding patterns.