The Central Medial Thalamic Nucleus Facilitates Bilateral Movement Execution in Rats.

Area of Science:

• Neuroscience
• Motor Control
• Thalamic Nuclei

Background:

• Intralaminar thalamic nuclei, particularly the central medial nucleus (CMT), are known for regulating attentional states like sleep-wake transitions.
• The CMT's extensive bilateral innervation of cortical and striatal sensorimotor areas suggests a role in motor function, though this is not fully understood.

Purpose of the Study:

• To investigate the contribution of the central medial nucleus (CMT) to motor control and coordination.
• To elucidate the role of CMT in bilateral sensorimotor processing and motor execution.

Main Methods:

• Utilized a novel behavioral protocol for evaluating bilateral coordination in rats.
• Employed electrophysiological recordings and optogenetic stimulation/inactivation of the CMT.
• Analyzed neural activity in sensorimotor cortex and striatum.

Main Results:

• Optogenetic stimulation of the CMT induced bilateral neural activity in sensorimotor cortex and striatum.
• CMT stimulation significantly enhanced bilateral forelimb coordination and decreased movement trajectory variability.
• CMT inactivation did not impair motor execution but increased task execution times, suggesting reduced engagement.

Conclusions:

• Brief CMT activations facilitate synchronized bilateral cortico-striatal activity.
• This synchronized activity is crucial for enhancing motor coordination on relevant temporal scales.
• The CMT plays a significant role in fine-tuning motor control and coordination.