title: CXCR4 is required for proper regional and laminar distribution of cortical somatostatin-, calretinin-, and neuropeptide Y-expressing GABAergic interneurons.
abstract: Cortical GABAergic interneurons are divided into various subtypes, with each subtype contributing to rich variety and fine details of inhibition. Despite the functional importance of each interneuron subtype, the molecular mechanisms that contribute to sorting them to their appropriate positions within the cortex remain unclear. Here, we show that the chemokine receptor CXCR4 regulates the regional and layer-specific distribution of interneuron subtypes. We removed Cxcr4 specifically in a subset of interneurons at a specific mouse embryonic developmental stage and analyzed the number of interneurons and their laminar distribution in 9 representative cortical regions comprehensively in adults. We found that the number of Cxcr4-deleted calretinin- and that of neuropeptide Y-expressing interneurons were reduced in most caudomedial and lateral cortical regions, respectively, and also in superficial layers. In addition, Cxcr4-deleted somatostatin-expressing interneurons showed a reduction in the number of superficial layers in certain cortical regions but of deep layers in others. These findings suggest that CXCR4 is required for proper regional and laminar distribution in a wider interneuron subpopulation than previously thought and may regulate the establishment of functional cortical circuitry in certain cortical regions and layers.
authors.affiliation: Department of Developmental Neuroscience, Graduate School of Frontier Biosciences, Osaka University, Suita, Osaka, Japan. dtanaka@sc.itc.keio.ac.jp
authors.forename: Daisuke H
authors.initials: DH
authors.lastname: Tanaka
authors.forename: Sakae
authors.initials: S
authors.lastname: Mikami
authors.forename: Takashi
authors.initials: T
authors.lastname: Nagasawa
authors.forename: Jun-ichi
authors.initials: J
authors.lastname: Miyazaki
authors.forename: Kazunori
authors.initials: K
authors.lastname: Nakajima
authors.forename: Fujio
authors.initials: F
authors.lastname: Murakami
mesh_terms: D000818:Animals; D064032:Calbindin 2; D002465:Cell Movement / Q000502:physiology; D002540:Cerebral Cortex / Q000166:cytology / Q000196:embryology* / Q000378:metabolism; D004622:Embryo, Mammalian; D007150:Immunohistochemistry; D007395:Interneurons / Q000166:cytology* / Q000378:metabolism; D051379:Mice; D008822:Mice, Transgenic; D055495:Neurogenesis / Q000502:physiology*; D009478:Neuropeptide Y / Q000096:biosynthesis; D016133:Polymerase Chain Reaction; D019718:Receptors, CXCR4 / Q000378:metabolism*; D064030:S100 Calcium Binding Protein G / Q000096:biosynthesis; D013004:Somatostatin / Q000096:biosynthesis; D005680:gamma-Aminobutyric Acid / Q000378:metabolism
chemical_list: C514936:CXCR4 protein, mouse; C576511:Calb2 protein, mouse; D064032:Calbindin 2; D009478:Neuropeptide Y; D019718:Receptors, CXCR4; D064030:S100 Calcium Binding Protein G; D013004:Somatostatin; D005680:gamma-Aminobutyric Acid