Dissociable Roles of Pallidal Neuron Subtypes in Regulating Motor Patterns

Area of Science:

• Neuroscience
• Cellular Biology
• Genetics

Background:

• The external globus pallidus (GPe) is crucial for motor control but its cellular complexity has limited understanding of its precise mechanisms.
• Existing driver lines inadequately capture the diversity of GPe neuron subclasses, hindering detailed investigation.

Purpose of the Study:

• To evaluate the utility of Kcng4-Cre, Npr3-Cre, and Npy2r-Cre mouse lines for delineating GPe neuron subtypes.
• To comprehensively investigate the electrophysiological and functional properties of GPe neuron subtypes.
• To elucidate the roles of distinct GPe neuron subtypes in motor regulation and behavior.

Main Methods:

• Utilized Kcng4-Cre, Npr3-Cre, and Npy2r-Cre transgenic mouse lines for cell-specific targeting.
• Conducted extensive electrophysiological recordings to characterize GPe neuron subtypes.
• Employed optogenetics combined with machine learning-based behavioral tracking to assess functional roles.

Main Results:

• Identified distinct GPe neuron subclasses, confirming PV+ and Npas1+ as major classes.
• Npr3+ neurons and Kcng4+ neurons were identified as distinct subclasses of Npas1+ and PV+ neurons, respectively.
• Optogenetic perturbation of GPe neuron subtypes elicited unique behavioral patterns, highlighting dissociable roles in movement and anxiety.

Conclusions:

• Genetically-defined GPe neuron subtypes play distinct roles in regulating motor patterns.
• Local inhibitory connections within the GPe influence the in vivo contributions of these neuron subtypes.
• Established new tools and foundational understanding for investigating GPe circuitry in motor function and dysfunction.