Extrasynaptic homomeric glycine receptors in neurons of the rat trigeminal mesencephalic nucleus.
Brain Struct Funct
; 223(5): 2259-2268, 2018 Jun.
Article
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| MEDLINE
| ID: mdl-29460053
ABSTRACT
The neurons in the trigeminal mesencephalic nucleus (Vmes) innervate jaw-closing muscle spindles and periodontal ligaments, and play a crucial role in the regulation of jaw movements. Recently, it was shown that many boutons that form synapses on them are immunopositive for glycine (Gly+), suggesting that these neurons receive glycinergic input. Information about the glycine receptors that mediate this input is needed to help understand the role of glycine in controlling Vmes neuron excitability. For this, we investigated the expression of glycine receptor subunit alpha 3 (GlyRα3) and gephyrin in neurons in Vmes and the trigeminal motor nucleus (Vmo), and the Gly+ boutons that contact them by light- and electron-microscopic immunocytochemistry and quantitative ultrastructural analysis. The somata of the Vmes neurons were immunostained for GlyRα3, but not gephyrin, indicating expression of homomeric GlyR. The immunostaining for GlyRα3 was localized away from the synapses in the Vmes neuron somata, in contrast to the Vmo neurons, where the staining for GlyRα3 and gephyrin were localized at the subsynaptic zones in somata and dendrites. Additionally, the ultrastructural determinants of synaptic strength, bouton volume, mitochondrial volume, and active zone area, were significantly smaller in Gly+ boutons on the Vmes neurons than in those on the Vmo neurons. These findings support the notion that the Vmes neurons receive glycinergic input via putative extrasynaptic homomeric glycine receptors, likely mediating a slow, tonic modulation of the Vmes neuron excitability.
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Texto completo:
1
Banco de datos:
MEDLINE
Asunto principal:
Receptores de Glicina
/
Terminales Presinápticos
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Núcleo Motor del Nervio Trigémino
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Neuronas
Límite:
Animals
Idioma:
En
Revista:
Brain Struct Funct
Asunto de la revista:
CEREBRO
Año:
2018
Tipo del documento:
Article
País de afiliación:
Corea del Sur