Cortico-thalamic communication for action coordination in a skilled motor sequence.

Area of Science:

• Neuroscience
• Motor Control
• Systems Neuroscience

Background:

• Coordinating forelimb and orofacial movements for feeding is crucial.
• Neural communication across brain regions underlies complex behaviors like reaching to consume.

Purpose of the Study:

• To identify the cortical network coordinating action progression in a mouse reach-and-withdraw-to-drink (RWD) behavior.
• To investigate the roles of different projection neuron types and output channels within the secondary motor cortex (MOs-c).

Main Methods:

• Wide-field imaging and photo-inhibition across the cortex.
• Electrophysiology and targeted photo-inhibition of projection neuron types in MOs-c.
• Analysis of neural activity during RWD behavior in mice.

Main Results:

• A specific cortical network, including the MOs-c, was identified for RWD behavior coordination.
• Corticothalamic (CT^MOs) output channels, but not pyramidal tract channels, showed sustained firing and selective enhancement of thalamic activity.
• CT^MOs neurons receive converging sensorimotor inputs and interact with thalamic neurons involved in action coordination.

Conclusions:

• The motor cortex corticothalamic channel plays a critical role in coordinating skilled motor sequences.
• This channel may amplify thalamic integration of sensorimotor information for precise action control.
• Understanding this circuit provides insights into the neural basis of complex motor behaviors.