title: Cytoarchitecture-Dependent Decrease in Propagation Velocity of Cortical Spreading Depression in the Rat Insular Cortex Revealed by Optical Imaging.
abstract: Cortical spreading depression (SD) is a self-propagating wave of depolarization accompanied by a substantial disturbance of the ionic distribution between the intra- and extracellular compartments. Glial cells, including astrocytes, play critical roles in maintenance of the extracellular environment, including ionic distribution. Therefore, SD propagation in the cerebral cortex may depend on the density of astrocytes. The present study aimed to examine the profile of SD propagation in the insular cortex (IC), which is located between the neocortex and paleocortex and is where the density of astrocytes gradually changes. The velocity of SD propagation in the neocortex, including the somatosensory, motor, and granular insular cortices (5.7 mm/min), was higher than that (2.8 mm/min) in the paleocortex (agranular insular and piriform cortices). Around thick vessels, including the middle cerebral artery, SD propagation was frequently delayed and sometimes disappeared. Immunohistological analysis of glial fibrillary acidic protein (GFAP) demonstrated the sparse distribution of astrocytes in the somatosensory cortex and the IC dorsal to the rhinal fissure, whereas the ventral IC showed a higher density of astrocytes. These results suggest that cortical cytoarchitectonic features, which possibly involve the distribution of astrocytes, are crucial for regulating the velocity of SD propagation in the cerebral cortex.
authors.affiliation: Department of Pharmacology, Dental Research Center, Nihon University School of Dentistry, 1-8-13 Kanda-Surugadai, Chiyoda-ku, Tokyo 101-8310, Japan.|Division of Oral and Craniomaxillofacial Research, Dental Research Center, Nihon University School of Dentistry, 1-8-13 Kanda-Surugadai, Chiyoda-ku, Tokyo 101-8310, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Fujita
authors.affiliation: Department of Pharmacology, Dental Research Center, Nihon University School of Dentistry, 1-8-13 Kanda-Surugadai, Chiyoda-ku, Tokyo 101-8310, Japan.|Division of Physiology, Department of Human Development and Fostering.
authors.forename: Naoko
authors.initials: N
authors.lastname: Mizoguchi
authors.affiliation: Department of Pharmacology, Dental Research Center, Nihon University School of Dentistry, 1-8-13 Kanda-Surugadai, Chiyoda-ku, Tokyo 101-8310, Japan.|Division of Oral and Maxillofacial Surgery, Department of Diagnostic and Therapeutic Sciences, Meikai University School of Dentistry, 1-1 Keyakidai, Sakado, Saitama 350-0283, Japan.
authors.forename: Ryuhei
authors.initials: R
authors.lastname: Aoki
authors.affiliation: Molecular Dynamics Imaging Unit, RIKEN Center for Life Science Technologies, 6-7-3 Minatojima-minamimachi, Chuo-ku, Kobe, Hyogo 650-0047, Japan.
authors.forename: Yilong
authors.initials: Y
authors.lastname: Cui
authors.affiliation: Department of Pharmacology, Dental Research Center, Nihon University School of Dentistry, 1-8-13 Kanda-Surugadai, Chiyoda-ku, Tokyo 101-8310, Japan.|Division of Oral and Craniomaxillofacial Research, Dental Research Center, Nihon University School of Dentistry, 1-8-13 Kanda-Surugadai, Chiyoda-ku, Tokyo 101-8310, Japan.
authors.forename: Noriaki
authors.initials: N
authors.lastname: Koshikawa
authors.affiliation: Department of Pharmacology, Dental Research Center, Nihon University School of Dentistry, 1-8-13 Kanda-Surugadai, Chiyoda-ku, Tokyo 101-8310, Japan.|Division of Oral and Craniomaxillofacial Research, Dental Research Center, Nihon University School of Dentistry, 1-8-13 Kanda-Surugadai, Chiyoda-ku, Tokyo 101-8310, Japan.|Molecular Dynamics Imaging Unit, RIKEN Center for Life Science Technologies, 6-7-3 Minatojima-minamimachi, Chuo-ku, Kobe, Hyogo 650-0047, Japan.
authors.forename: Masayuki
authors.initials: M
authors.lastname: Kobayashi
mesh_terms: D000818:Animals; D001253:Astrocytes / Q000378:metabolism*; D002540:Cerebral Cortex / Q000378:metabolism / Q000503:physiopathology*; D013181:Cortical Spreading Depression; D008297:Male; D061848:Optical Imaging; D051381:Rats; D017207:Rats, Sprague-Dawley; D013003:Somatosensory Cortex / Q000378:metabolism / Q000503:physiopathology
keywords: astrocytes; insula; middle cerebral artery; paleocortex; piriform cortex