title: Development of layer 1 neurons in the mouse neocortex.
abstract: Layer 1 of the neocortex harbors a unique group of neurons that play crucial roles in synaptic integration and information processing. Although extensive studies have characterized the properties of layer 1 neurons in the mature neocortex, it remains unclear how these neurons progressively acquire their distinct morphological, neurochemical, and physiological traits. In this study, we systematically examined the dynamic development of Cajal-Retzius cells and γ-aminobutyric acid (GABA)-ergic interneurons in layer 1 during the first 2 postnatal weeks. Cajal-Retzius cells underwent morphological degeneration after birth and gradually disappeared from layer 1. The majority of GABAergic interneurons showed clear expression of at least 1 of the 6 distinct neurochemical markers, including Reelin, GABA-A receptor subunit delta (GABAARδ), neuropeptide Y, vasoactive intestinal peptide (VIP), calretinin, and somatostatin from postnatal day 8. Furthermore, according to firing pattern, layer 1 interneurons can be divided into 2 groups: late-spiking (LS) and burst-spiking (BS) neurons. LS neurons preferentially expressed GABAARδ, whereas BS neurons preferentially expressed VIP. Interestingly, both LS and BS neurons exhibited a rapid electrophysiological and morphological development during the first postnatal week. Our results provide new insights into the molecular, morphological, and functional developments of the neurons in layer 1 of the neocortex.
authors.affiliation: Institute of Neurobiology, Institutes of Brain Science and State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai 200032, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Ma
authors.affiliation: Institute of Neurobiology, Institutes of Brain Science and State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai 200032, China.
authors.forename: Xing-Hua
authors.initials: XH
authors.lastname: Yao
authors.affiliation: Institute of Neurobiology, Institutes of Brain Science and State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai 200032, China.
authors.forename: Yinghui
authors.initials: Y
authors.lastname: Fu
authors.affiliation: Institute of Neurobiology, Institutes of Brain Science and State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai 200032, China.
authors.forename: Yong-Chun
authors.initials: YC
authors.lastname: Yu
mesh_terms: D000200:Action Potentials; D000818:Animals; D064032:Calbindin 2 / Q000032:analysis; D015816:Cell Adhesion Molecules, Neuronal / Q000032:analysis; D002452:Cell Count; D016326:Extracellular Matrix Proteins / Q000032:analysis; D059330:GABAergic Neurons / Q000166:cytology* / Q000378:metabolism / Q000502:physiology*; D007395:Interneurons / Q000166:cytology / Q000378:metabolism / Q000502:physiology; D051379:Mice; D008822:Mice, Transgenic; D019579:Neocortex / Q000166:cytology* / Q000254:growth & development*; D009419:Nerve Tissue Proteins / Q000032:analysis; D009474:Neurons / Q000166:cytology* / Q000378:metabolism / Q000502:physiology*; D009478:Neuropeptide Y / Q000032:analysis; D011963:Receptors, GABA-A / Q000032:analysis; D000091042:Reelin Protein; D012697:Serine Endopeptidases / Q000032:analysis; D013004:Somatostatin / Q000032:analysis; D014660:Vasoactive Intestinal Peptide / Q000032:analysis
chemical_list: C576511:Calb2 protein, mouse; D064032:Calbindin 2; D015816:Cell Adhesion Molecules, Neuronal; D016326:Extracellular Matrix Proteins; D009419:Nerve Tissue Proteins; D009478:Neuropeptide Y; D011963:Receptors, GABA-A; D000091042:Reelin Protein; D014660:Vasoactive Intestinal Peptide; D013004:Somatostatin; C000717128:Reln protein, mouse; D012697:Serine Endopeptidases
keywords: Cajal-Retzius cells; interneurons; layer 1; neocortex