Distribution of Gephyrin-Immunoreactivity in the Trigeminal Motor Nucleus: An Immunohistochemical Study in Rats

Authors

  • Zhihong Li,

    1. Department of Anatomy, Histology and Embryology and K.K. Leung Brain Research Centre, The Fourth Military Medical University, Xi'an, China
    2. Department of Neurosurgery, Tangdu Hospital, The Fourth Military Medical University, Xi'an, China
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    • Zhihong Li and Shunnan Ge contributed equally to this work.

  • Shunnan Ge,

    1. Department of Anatomy, Histology and Embryology and K.K. Leung Brain Research Centre, The Fourth Military Medical University, Xi'an, China
    2. Department of Neurosurgery, Tangdu Hospital, The Fourth Military Medical University, Xi'an, China
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    • Zhihong Li and Shunnan Ge contributed equally to this work.

  • Fuxing Zhang,

    1. Department of Anatomy, Histology and Embryology and K.K. Leung Brain Research Centre, The Fourth Military Medical University, Xi'an, China
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  • Ting Zhang,

    1. Department of Anatomy, Histology and Embryology and K.K. Leung Brain Research Centre, The Fourth Military Medical University, Xi'an, China
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  • Noboru Mizuno,

    1. Department of Morphological Brain Science, Graduate School of Medicine, Kyoto University, Kyoto, Japan
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  • Hiroyuki Hioki,

    1. Department of Morphological Brain Science, Graduate School of Medicine, Kyoto University, Kyoto, Japan
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  • Takeshi Kaneko,

    1. Department of Morphological Brain Science, Graduate School of Medicine, Kyoto University, Kyoto, Japan
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  • Guodong Gao,

    Corresponding author
    1. Department of Neurosurgery, Tangdu Hospital, The Fourth Military Medical University, Xi'an, China
    • Department of Neurosurgery, Tangdu Hospital, The Fourth Military Medical University, Xi'an 710038, China
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    • Fax: 86-29-84777435

  • Jinlian Li

    Corresponding author
    1. Department of Anatomy, Histology and Embryology and K.K. Leung Brain Research Centre, The Fourth Military Medical University, Xi'an, China
    • Department of Anatomy, Histology and Embryology and K.K. Leung Brain Research Centre, The Fourth Military Medical University, Xi'an 710032, China
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    • Fax: 86-29-83-283-229


Abstract

It has been established that a postsynaptic scaffolding protein, gephyrin, is essential for anchoring two main groups of inhibitory receptors, GABAA receptors (GABAARs) and glycine receptors (GlyRs), to the postsynaptic sites of neurons. The present study was primarily attempted to examine if expression patterns of gephyrin might be different between jaw-closing (JC) and jaw-opening (JO) motoneurons. The JC- and JO-motoneurons in the rat trigeminal motor nucleus (Vm) were located in the dorsolateral (Vm.dl) and ventromedial (Vm.vm) divisions, respectively (Mizuno et al.,1975). Thus, immunoreactivity (IR) for gephyrin was investigated in the Vm: immunofluorescence histochemistry for gephyrin was combined with retrograde tract-tracing of fluorogold (FG), which was injected into nerves innervating JC-muscles or nerves innervating JO-muscles; neuronal cells were counterstained with propidium iodide (PI). The Vm.dl was discriminated from the Vm.vm by the presence of vesicular glutamate transporter 1 (VGLUT1)-immunopositive axon terminals, which were distributed in the Vm.dl but not in the Vm.vm (Pang et al., J Comp Neurol2009;512:595–612). Gephyrin-IR showed a punctate pattern of fluorescence, and motoneuronal profiles were coated with small clusters of gephyrin-immunopositive puncta throughout the Vm. The distribution density of such clusters was apparently higher in the Vm.dl than in the Vm.vm; this was confirmed quantitatively by a method similar to that described by Lorenzo et al. (Eur J Neurosci2006;23:3161–3170). On the basis of the present results, possible correlation between the distribution density of gephyrin clusters in the submembrane region of Vm motoneurons and that of axon terminals making inhibitory synapses on Vm motoneurons was discussed. Anat Rec, 2012. © 2012 Wiley Periodicals, Inc.

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