A cortical circuit for orchestrating oromanual food manipulation.

The seamless coordination of hand and mouth during feeding is a sophisticated motor skill characteristic of rodents and primates. While spinal and brainstem circuits mediate elemental forelimb and orofacial actions, whether dedicated neocortical circuits assemble these actions into ethological feeding movements remains unclear. Through systematic optogenetic screening, we identify the rostral forelimb-orofacial area (RFO), where activation of either pyramidal tract (PTFezf2) or intratelencephalic (ITPlxnD1) neurons elicits coordinated forelimb and orofacial movements resembling natural eating. RFO connects reciprocally with forelimb and orofacial sensorimotor cortices: while PTsFezf2 project to subcortical motor centers driving effector movements, ITsPlxnD1 target cortical areas and ventrolateral striatum mediating oromanual coordination. During free-moving eating behaviors, activities of both PTsFezf2 and ITsPlxnD1 are correlated with oromanual manipulation, yet silencing reveals distinct functions: PTsFezf2 for dexterous hand-mouth movements and ITsPlxnD1 for their temporal coordination. These findings define a cell-type-specific motor cortical circuit that orchestrates the multi-effector coordination underlying natural feeding.

Duke Scholars

Author Josh Huang Neurobiology