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Differential localization of γ‐aminobutyric acid type a and glycine receptor subunits and gephyrin in the human pons, medulla oblongata and uppermost cervical segment of the spinal cord: An immunohistochemical study
Author(s) -
Waldvogel H.J.,
Baer K.,
Eady E.,
Allen K.L.,
Gilbert R.T.,
Mohler H.,
Rees M.I.,
Nicholson L.F.B.,
Faull R.L.M.
Publication year - 2009
Publication title -
journal of comparative neurology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.855
H-Index - 209
eISSN - 1096-9861
pISSN - 0021-9967
DOI - 10.1002/cne.22212
Subject(s) - gephyrin , glycine receptor , medulla oblongata , spinal cord , spinal trigeminal nucleus , biology , inferior olivary nucleus , pons , brainstem , serotonergic cell groups , neuroscience , inhibitory postsynaptic potential , anatomy , raphe nuclei , dorsal column nuclei , nucleus , receptor , central nervous system , serotonergic , glycine , nociception , biochemistry , amino acid , serotonin
Gephyrin is a multifunctional protein responsible for the clustering of glycine receptors (GlyR) and γ‐aminobutyric acid type A receptors (GABA A R). GlyR and GABA A R are heteropentameric chloride ion channels that facilitate fast‐response, inhibitory neurotransmission in the mammalian brain and spinal cord. We investigated the immunohistochemical distribution of gephyrin and the major GABA A R and GlyR subunits in the human light microscopically in the rostral and caudal one‐thirds of the pons, in the middle and caudal one‐thirds of the medulla oblongata, and in the first cervical segment of the spinal cord. The results demonstrate a widespread pattern of immunoreactivity for GlyR and GABA A R subunits throughout these regions, including the spinal trigeminal nucleus, abducens nucleus, facial nucleus, pontine reticular formation, dorsal motor nucleus of the vagus nerve, hypoglossal nucleus, lateral cuneate nucleus, and nucleus of the solitary tract. The GABA A R α 1 and GlyR α 1 and β subunits show high levels of immunoreactivity in these nuclei. The GABA A R subunits α 2 , α 3 , β 2,3 , and γ 2 present weaker levels of immunoreactivity. Exceptions are intense levels of GABA A R α 2 subunit immunoreactivity in the inferior olivary complex and high levels of GABA A R α 3 subunit immunoreactivity in the locus coeruleus and raphe nuclei. Gephyrin immunoreactivity is highest in the first segment of the cervical spinal cord and hypoglossal nucleus. Our results suggest that a variety of different inhibitory receptor subtypes is responsible for inhibitory functions in the human brainstem and cervical spinal cord and that gephyrin functions as a clustering molecule for major subtypes of these inhibitory neurotransmitter receptors. J. Comp. Neurol. 518:305–328, 2010. © 2009 Wiley‐Liss, Inc.