Genomic-anatomic evidence for distinct functional domains in hippocampal field CA1.

TitleGenomic-anatomic evidence for distinct functional domains in hippocampal field CA1.
Publication TypeJournal Article
Year of Publication2009
AuthorsDong, H-W, Swanson LW, Chen L, Fanselow MS, Toga AW
JournalProceedings of the National Academy of Sciences of the United States of America
Date Published2009 Jul 14
KeywordsAnimals, Brain Mapping, Cell Differentiation, Gene Expression Profiling, Gene Library, Hippocampus, Mice, Pyramidal Cells

Functional heterogeneity has been investigated for decades in the hippocampal region of the mammalian cerebral cortex, and evidence for vaguely defined "dorsal" and "ventral" regions is emerging. Direct evidence that hippocampal field CA1 displays clear regional, laminar, and pyramidal neuron differentiation is presented here, based on a systematic high-resolution analysis of a publicly accessible, genome-wide expression digital library (Allen Brain Atlas) [Lein et al. (2007) Genome-wide atlas of gene expression in the adult mouse brain. Nature 445:168-176]. First, genetic markers reveal distinct spatial expression domains and subdomains along the longitudinal (dorsal/septal/posterior to ventral/temporal/anterior) axis of field CA1. Second, genetic markers divide field CA1 pyramidal neurons into multiple subtypes with characteristic laminar distributions. And third, subcortical brain regions receiving axonal projections from molecularly distinct spatial domains of field CA1 display distinct global gene expression patterns, suggesting that field CA1 spatial domains may be genetically wired independently to form distinct functional networks related to cognition and emotion. Insights emerging from this genomic-anatomic approach provide a starting point for a detailed analysis of differential hippocampal structure-function organization.

Alternate JournalProc. Natl. Acad. Sci. U.S.A.