epDevAtlas: mapping GABAergic cells and microglia in the early postnatal mouse brain

Area of Science:

• Neuroscience
• Developmental Biology
• Computational Biology

Background:

• Brain development follows specific growth trajectories, but detailed regional and cellular changes are not fully understood.
• Classical growth charts lack the resolution to capture regional volumetric growth and cell type dynamics.
• Understanding early postnatal brain development is crucial for identifying typical and pathological deviations.

Purpose of the Study:

• To create high-resolution 3D atlases of the early postnatal mouse brain.
• To quantify regional volumetric growth and cell type-specific density changes.
• To provide an open-access resource for studying brain development.

Main Methods:

• Generation of high-resolution 3D brain atlases at multiple postnatal time points (P4-14) using Allen CCFv3.
• Utilization of 11 cell type-specific transgenic mouse lines for anatomical label validation.
• Analysis of volumetric growth and cell densities, including GABAergic neurons, cortical interneurons, and microglia.

Main Results:

• Detailed volumetric growth trajectories for various mouse brain regions were mapped.
• Region-specific density changes were identified for GABAergic neurons, with distinct patterns in cortical and striatal areas.
• Microglia exhibited dynamic spatial redistribution and selective density increases in sensory processing areas correlating with sensory modality emergence.

Conclusions:

• High-definition atlases provide a quantitative framework for understanding early postnatal brain development.
• Cellular dynamics, particularly of GABAergic neurons and microglia, play critical roles in shaping brain development.
• The open-access visualization tool facilitates further research into developmental trajectories and associated pathologies.