Beyond the Brake: the Subthalamic Nucleus Predominantly Facilitates Action in Non-human Primates

Area of Science:

• Neuroscience
• Decision Neuroscience
• Motor Control

Background:

• The subthalamic nucleus (STN) is traditionally considered a suppressor of motor output.
• Its role in complex behaviors like decision-making remains less understood.

Purpose of the Study:

• To investigate the function of the subthalamic nucleus (STN) in value-based decision-making.
• To challenge the classical model of the STN as solely a motor brake.

Main Methods:

• Recorded single-neuron activity from the primate STN during a choice task.
• Analyzed neuron firing patterns and response latencies.
• Utilized population-level analyses to decode neural representations.

Main Results:

• Identified functionally distinct neuron clusters within the STN.
• Found that approximately 89% of task-related neurons exhibited action facilitation, not suppression.
• Facilitative neurons increased firing for rewarded choices and predicted reaction times.
• Demonstrated robust encoding of upcoming choices by facilitative STN populations.

Conclusions:

• The STN plays a dual role, with a predominant function in facilitating desired actions.
• Findings challenge the traditional view of the STN as exclusively a motor suppressor.
• The STN is actively involved in guiding choices and action initiation.