Sharp cell-type-identity changes differentiate the retrosplenial cortex from the neocortex
Kaitlin E. Sullivan,
Larissa Kraus,
Margarita Kapustina,
Lihua Wang,
Tara R. Stach,
Andrew L. Lemire,
Jody Clements,
Mark S. Cembrowski
Affiliations
Kaitlin E. Sullivan
Department of Cellular and Physiological Sciences, Life Sciences Institute, University of British Columbia, 2350 Health Sciences Boulevard, Vancouver, BC, Canada
Larissa Kraus
Department of Cellular and Physiological Sciences, Life Sciences Institute, University of British Columbia, 2350 Health Sciences Boulevard, Vancouver, BC, Canada
Margarita Kapustina
Department of Cellular and Physiological Sciences, Life Sciences Institute, University of British Columbia, 2350 Health Sciences Boulevard, Vancouver, BC, Canada
Lihua Wang
Djavad Mowafaghian Centre for Brain Health, University of British Columbia, 2215 Wesbrook Mall, Vancouver, BC, Canada
Tara R. Stach
School of Biomedical Engineering, Biomedical Research Centre, University of British Columbia, 2222 Health Sciences Mall, Vancouver, BC, Canada
Andrew L. Lemire
Djavad Mowafaghian Centre for Brain Health, University of British Columbia, 2215 Wesbrook Mall, Vancouver, BC, Canada
Jody Clements
Djavad Mowafaghian Centre for Brain Health, University of British Columbia, 2215 Wesbrook Mall, Vancouver, BC, Canada
Mark S. Cembrowski
Department of Cellular and Physiological Sciences, Life Sciences Institute, University of British Columbia, 2350 Health Sciences Boulevard, Vancouver, BC, Canada; Djavad Mowafaghian Centre for Brain Health, University of British Columbia, 2215 Wesbrook Mall, Vancouver, BC, Canada; Janelia Research Campus, HHMI, 19700 Helix Dr, Ashburn, VA, USA; Corresponding author
Summary: The laminae of the neocortex are fundamental processing layers of the mammalian brain. Notably, such laminae are believed to be relatively stereotyped across short spatial scales such that shared laminae between nearby brain regions exhibit similar constituent cells. Here, we consider a potential exception to this rule by studying the retrosplenial cortex (RSC), a brain region known for sharp cytoarchitectonic differences across its granular-dysgranular border. Using a variety of transcriptomics techniques, we identify, spatially map, and interpret the excitatory cell-type landscape of the mouse RSC. In doing so, we uncover that RSC gene expression and cell types change sharply at the granular-dysgranular border. Additionally, supposedly homologous laminae between the RSC and the neocortex are effectively wholly distinct in their cell-type composition. In collection, the RSC exhibits a variety of intrinsic cell-type specializations and embodies an organizational principle wherein cell-type identities can vary sharply within and between brain regions.
