Extrasynaptic homomeric glycine receptors in neurons of the rat trigeminal mesencephalic nucleus

Jin Young Bae, Jae Sik Lee, Sang Jin Ko, Yi Sul Cho, Jong Cheol Rah, Hee Jung Cho, Mae Ja Park, Yong Chul Bae

Research output: Contribution to journalArticlepeer-review

4 Scopus citations

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.

Original languageEnglish
Pages (from-to)2259-2268
Number of pages10
JournalBrain Structure and Function
Volume223
Issue number5
DOIs
StatePublished - 1 Jun 2018

Keywords

  • Glycine receptor
  • Homomeric
  • Immunohistochemistry
  • Jaw movement
  • Mesencephalic trigeminal nucleus
  • Ultrastructure

Fingerprint

Dive into the research topics of 'Extrasynaptic homomeric glycine receptors in neurons of the rat trigeminal mesencephalic nucleus'. Together they form a unique fingerprint.

Cite this