Patchy Striatonigral Neurons Modulate Locomotor Vigor in Response to Environmental Valence

Area of Science:

• Neuroscience
• Motor Control
• Behavioral Neuroscience

Background:

• Spiny projection neurons (SPNs) in the dorsal striatum are vital for locomotion and decision-making.
• SPNs are diverse, with subtypes defined by transcriptomics and distribution, but their role in valence-driven locomotion is unclear.

Purpose of the Study:

• To investigate how specific SPN subtypes regulate spontaneous locomotion in response to environmental valence.
• To identify the role of patchy striatonigral neurons in modulating walking speed and zone discrimination.

Main Methods:

• Utilized Sepw1-Cre transgenic mice to target a specific SPN subtype with patchy distribution.
• Employed a modified light/dark box test to assess locomotion and zone preference.
• Conducted in vivo recordings and chemogenetic/optical manipulations to examine neuronal activity and function.

Main Results:

• Patchy striatonigral neurons were found to constrain motor vigor, particularly during transitions between differently valenced environments.
• Genetic ablation of these neurons disrupted normal slowing in the dark zone and altered speed-based zone discrimination.
• Neuronal activity correlated with zone occupancy, speed, and deceleration, highlighting their role in mediating deceleration.

Conclusions:

• A specific subtype of patchy striatonigral neurons plays a critical role in regulating implicit walking speed selection based on innate environmental valence.
• These findings elucidate a novel mechanism by which SPN subtypes contribute to adaptive motor behavior in response to environmental cues.