title: Identification of cells expressing Cx43, Cx30, Cx26, Cx32 and Cx36 in gap junctions of rat brain and spinal cord.
abstract: We have identified cells expressing Cx26, Cx30, Cx32, Cx36 and Cx43 in gap junctions of rat central nervous system (CNS) using confocal light microscopic immunocytochemistry and freeze-fracture replica immunogold labeling (FRIL). Confocal microscopy was used to assess general distributions of connexins, whereas the 100-fold higher resolution of FRIL allowed co-localization of several different connexins within individual ultrastructurally-defined gap junction plaques in ultrastructurally and immunologically identified cell types. In >4000 labeled gap junctions found in >370 FRIL replicas of gray matter in adult rats, Cx26, Cx30 and Cx43 were found only in astrocyte gap junctions; Cx32 was only in oligodendrocytes, and Cx36 was only in neurons. Moreover, Cx26, Cx30 and Cx43 were co-localized in most astrocyte gap junctions. Oligodendrocytes shared intercellular gap junctions only with astrocytes, and these heterologous junctions had Cx32 on the oligodendrocyte side and Cx26, Cx30 and Cx43 on the astrocyte side. In 4 and 18 day postnatal rat spinal cord, neuronal gap junctions contained Cx36, whereas Cx26 was present in leptomenigeal gap junctions. Thus, in adult rat CNS, neurons and glia express different connexins, with "permissive" connexin pairing combinations apparently defining separate pathways for neuronal vs. glial gap junctional communication.
authors.affiliation: Department of Biomedical Sciences, Colorado State University, Fort Collins 80523, USA. john.rash@colostate.edu
authors.forename: J E
authors.initials: JE
authors.lastname: Rash
authors.forename: T
authors.initials: T
authors.lastname: Yasumura
authors.forename: K G
authors.initials: KG
authors.lastname: Davidson
authors.forename: C S
authors.initials: CS
authors.lastname: Furman
authors.forename: F E
authors.initials: FE
authors.lastname: Dudek
authors.forename: J I
authors.initials: JI
authors.lastname: Nagy
mesh_terms: D000367:Age Factors; D000818:Animals; D001921:Brain / Q000166:cytology / Q000378:metabolism*; D002450:Cell Communication / Q000502:physiology; D000072259:Connexin 26; D000075302:Connexin 30; D018031:Connexin 43 / Q000378:metabolism*; D017630:Connexins / Q000378:metabolism*; D005614:Freeze Fracturing / Q000379:methods; D017629:Gap Junctions / Q000737:chemistry; D018613:Microscopy, Confocal; D008953:Models, Anatomic; D009457:Neuroglia / Q000737:chemistry / Q000648:ultrastructure; D009474:Neurons / Q000737:chemistry / Q000648:ultrastructure; D051381:Rats; D013116:Spinal Cord / Q000166:cytology / Q000378:metabolism*; D000097002:Gap Junction beta-1 Protein; D000097004:Gap Junction delta-2 Protein
chemical_list: D000072259:Connexin 26; D000075302:Connexin 30; D018031:Connexin 43; D017630:Connexins; D000097002:Gap Junction beta-1 Protein; D000097004:Gap Junction delta-2 Protein; C000607042:GJB2 protein, human; C491020:GJB6 protein, human; C000607044:Gjb2 protein, rat