A Cross-Species Enhancer-AAV Toolkit for Cell Type-Specific Targeting Across the Basal Ganglia

Area of Science:

• Neuroscience
• Genetics
• Molecular Biology

Background:

• The basal ganglia (BG) are crucial for motor, cognitive, and affective functions.
• Limited cell type-specific genetic tools exist for BG research, particularly across species.
• Key BG structures like the pallidum and subthalamic nucleus are implicated in neurological and psychiatric disorders.

Purpose of the Study:

• To create a comprehensive enhancer-AAV library for selective genetic targeting of major BG neuronal populations.
• To enable cross-species manipulation and labeling of BG cell types, including projection neurons, pallidal neurons, subthalamic neurons, and midbrain dopaminergic/GABAergic populations.
• To facilitate circuit dissection in disorders affecting the basal ganglia.

Main Methods:

• Development of a comprehensive enhancer-AAV library.
• Utilizing an evolutionarily informed discovery pipeline to identify enhancers.
• Validation of enhancer specificity and cross-species conservation (mouse and macaque).
• Computational modeling to predict in vivo enhancer performance based on sequence features.

Main Results:

• Successful identification and validation of enhancers targeting diverse BG neuronal populations.
• Demonstrated robust cross-species conservation of enhancer specificity between mouse and macaque.
• Revealed predictive sequence features for enhancer performance, including motif grammar, chromatin accessibility, and evolutionary conservation.
• Identified distinct regulatory architectures across different neuronal lineages within the BG.

Conclusions:

• A comprehensive cross-species viral toolkit for the mammalian basal ganglia has been established.
• This toolkit enables selective targeting of previously inaccessible BG cell types.
• The findings unlock new possibilities for circuit dissection and understanding BG function in health and disease.