title: Distinct development of the glycinergic terminals in the ventral and dorsal horns of the mouse cervical spinal cord.
abstract: In the spinal cord, glycine and γ-amino butyric acid (GABA) are inhibitory neurotransmitters. However, the ontogeny of the glycinergic network remains unclear. To address this point, we examined the developmental formation of glycinergic terminals by immunohistochemistry for glycine transporter 2 (GlyT2), a marker of glycinergic terminals, in developing mouse cervical spinal cord. Furthermore, the developmental localization of GlyT2 was compared with that of glutamic acid decarboxylase (GAD), a marker of GABAergic terminals, and vesicular GABA transporter (VGAT), a marker of inhibitory terminals, by single and double immunolabeling. GlyT2-positive dots (glycinergic terminals) were first detected in the marginal zone on embryonic day 14 (E14). In the ventral horn, they were detected at E16 and increased in observed density during postnatal development. Until postnatal day 7 (P7), GAD-positive dots (GABAergic terminals) were dominant and GlyT2 immunolabeling was localized at GAD-positive dots. During the second postnatal week, GABAergic terminals markedly decreased and glycinergic terminals became dominant. In the dorsal horn, glycinergic terminals were detected at P0 in lamina IV and P7 in lamina III and developmentally increased. GlyT2 was also localized at GAD-positive dots, and colocalizing dots were dominant at P21. VGAT-positive dots (inhibitory terminals) continued to increase until P21. These results suggest that GABAergic terminals first appear during embryonic development and may often change to colocalizing terminals throughout the gray matter during development. The colocalizing terminals may remain in the dorsal horn, whereas in the ventral horn, colocalizing terminals may give rise to glycinergic terminals.
authors.affiliation: Department of Molecular Anatomy, School of Medicine, University of the Ryukyus, 207 Uehara 207, Nishihara, Okinawa 9030215, Japan.
authors.forename: Masanobu
authors.initials: M
authors.lastname: Sunagawa
authors.affiliation: Department of Molecular Anatomy, School of Medicine, University of the Ryukyus, 207 Uehara 207, Nishihara, Okinawa 9030215, Japan.
authors.forename: Chigusa
authors.initials: C
authors.lastname: Shimizu-Okabe
authors.affiliation: Department of Molecular Anatomy, School of Medicine, University of the Ryukyus, 207 Uehara 207, Nishihara, Okinawa 9030215, Japan.
authors.forename: Jeongtae
authors.initials: J
authors.lastname: Kim
authors.affiliation: Department of Molecular Anatomy, School of Medicine, University of the Ryukyus, 207 Uehara 207, Nishihara, Okinawa 9030215, Japan.
authors.forename: Shiori
authors.initials: S
authors.lastname: Kobayashi
authors.affiliation: Department of Molecular Anatomy, School of Medicine, University of the Ryukyus, 207 Uehara 207, Nishihara, Okinawa 9030215, Japan.
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Kosaka
authors.affiliation: Division of Neuroscience, Genetic and Behavioral Neuroscience, Gunma University Graduate School of Medicine, Maebashi, Gunma 3718511, Japan.
authors.forename: Yuchio
authors.initials: Y
authors.lastname: Yanagawa
authors.affiliation: Department of Molecular and Cellular Physiology, School of Medicine, University of the Ryukyus, 207 Uehara, Nishihara, Okinawa 9030215, Japan.
authors.forename: Masayuki
authors.initials: M
authors.lastname: Matsushita
authors.affiliation: Department of Molecular Anatomy, School of Medicine, University of the Ryukyus, 207 Uehara 207, Nishihara, Okinawa 9030215, Japan.
authors.forename: Akihito
authors.initials: A
authors.lastname: Okabe
authors.affiliation: Department of Molecular Anatomy, School of Medicine, University of the Ryukyus, 207 Uehara 207, Nishihara, Okinawa 9030215, Japan. Electronic address: takachan@med.u-ryukyu.ac.jp.
authors.forename: Chitoshi
authors.initials: C
authors.lastname: Takayama
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D000870:Anterior Horn Cells / Q000166:cytology / Q000378:metabolism*; D066193:Cervical Cord / Q000166:cytology / Q000254:growth & development* / Q000378:metabolism*; D005998:Glycine / Q000378:metabolism*; D050487:Glycine Plasma Membrane Transport Proteins / Q000378:metabolism; D007150:Immunohistochemistry; D008297:Male; D008854:Microscopy, Electron; D020671:Posterior Horn Cells / Q000166:cytology / Q000378:metabolism*; D013569:Synapses / Q000378:metabolism*; D050495:Vesicular Inhibitory Amino Acid Transport Proteins / Q000378:metabolism; D005680:gamma-Aminobutyric Acid / Q000378:metabolism
chemical_list: D050487:Glycine Plasma Membrane Transport Proteins; C493270:Slc6a5 protein, mouse; D050495:Vesicular Inhibitory Amino Acid Transport Proteins; C492244:Viaat protein, mouse; D005680:gamma-Aminobutyric Acid; D005998:Glycine
keywords: glutamic acid decarboxylase; glycine; glycine transporter 2; inhibitory synapse; vesicular GABA transporter; γ-amino butyric acid