title: Immunoreactivity for the NMDA NR1 subunit in bulbospinal catecholamine and serotonin neurons of rat ventral medulla.
abstract: Bulbospinal neurons in the ventral medulla play important roles in the regulation of sympathetic outflow. Physiological evidence suggests that these neurons are activated by N-methyl-D-aspartate (NMDA) and non-NMDA subtypes of glutamate receptors. In this study, we examined bulbospinal neurons in the ventral medulla for the presence of immunoreactivity for the NMDA NR1 subunit, which is essential for NMDA receptor function. Rats received bilateral injections of cholera toxin B into the tenth thoracic spinal segment to label bulbospinal neurons. Triple immunofluorescent labeling was used to detect cholera toxin B with a blue fluorophore, NR1 with a red fluorophore, and either tyrosine hydroxylase or tryptophan hydroxylase with a green fluorophore. In the rostral ventrolateral medulla, NR1 occurred in all bulbospinal tyrosine hydroxylase-positive neurons and 96% of bulbospinal tyrosine hydroxylase-negative neurons, which were more common in sections containing the facial nucleus. In the raphe pallidus, the parapyramidal region, and the marginal layer, 98% of bulbospinal tryptophan hydroxylase-positive neurons contained NR1 immunoreactivity. NR1 was also present in all of the bulbospinal tryptophan hydroxylase-negative neurons, which comprised 20% of bulbospinal neurons in raphe pallidus and the parapyramidal region. These results show that virtually all bulbospinal tyrosine hydroxylase and non-tyrosine hydroxylase neurons in the rostral ventrolateral medulla and virtually all bulbospinal serotonin and non-serotonin neurons in raphe pallidus and the parapyramidal region express NR1, the obligatory subunit of the NMDA receptor. NMDA receptors on bulbospinal neurons in the rostral ventral medulla likely influence sympathoexcitation in normal and pathological conditions.
authors.affiliation: Cardiovascular Medicine, Physiology and Centre for Neuroscience, School of Medicine, Flinders University, Bedford Park, SA 5042, Australia; Department of Physiology, Wayne State University School of Medicine, Detroit, MI, USA.
authors.forename: Ida J
authors.initials: IJ
authors.lastname: Llewellyn-Smith
authors.forename: Patrick J
authors.initials: PJ
authors.lastname: Mueller
mesh_terms: D000818:Animals; D002395:Catecholamines / Q000032:analysis / Q000096:biosynthesis*; D008297:Male; D008526:Medulla Oblongata / Q000737:chemistry / Q000378:metabolism*; D021122:Protein Subunits / Q000032:analysis / Q000096:biosynthesis*; D011712:Pyramidal Tracts / Q000737:chemistry / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D016194:Receptors, N-Methyl-D-Aspartate / Q000032:analysis / Q000096:biosynthesis*; D059326:Serotonergic Neurons / Q000737:chemistry / Q000378:metabolism*
chemical_list: D002395:Catecholamines; C409466:NR1 NMDA receptor; D021122:Protein Subunits; D016194:Receptors, N-Methyl-D-Aspartate
keywords: C1 neurons; Glutamate; autonomic; medulla oblongata; tryptophan hydroxylase; tyrosine hydroxylase
references.citation: J Appl Physiol (1985). 2010 May;108(5):1425-32
references.pmid: 20133432
references.citation: Hypertension. 2010 Feb;55(2):284-90
references.pmid: 20065145
references.citation: Arch Histol Cytol. 2001 Aug;64(3):281-94
references.pmid: 11575424
references.citation: J Comp Neurol. 2002 Mar 12;444(3):191-206
references.pmid: 11840474
references.citation: J Comp Neurol. 1995 Apr 3;354(2):193-208
references.pmid: 7782498
references.citation: Brain Res. 1981 Apr 27;211(1):146-52
references.pmid: 6164449
references.citation: J Comp Neurol. 2005 Aug 1;488(3):278-89
references.pmid: 15952166
references.citation: Am J Physiol Regul Integr Comp Physiol. 2004 Oct;287(4):R824-32
references.pmid: 15205184
references.citation: J Comp Neurol. 1984 Sep 10;228(2):168-85
references.pmid: 6480910
references.citation: J Comp Neurol. 1992 Oct 1;324(1):1-13
references.pmid: 1401261
references.citation: Pharmacol Rev. 1999 Mar;51(1):7-61
references.pmid: 10049997
references.citation: Brain Res Bull. 1995;37(5):513-21
references.pmid: 7633899
references.citation: J Neurosci. 2000 Sep 1;20(17):6578-86
references.pmid: 10964963
references.citation: J Neurosci. 2004 Jun 9;24(23):5370-80
references.pmid: 15190110
references.citation: Arch Histol Cytol. 1994 May;57(2):139-50
references.pmid: 7520718
references.citation: J Appl Physiol (1985). 2010 Apr;108(4):995-1002
references.pmid: 20075262
references.citation: J Comp Neurol. 2004 Apr 12;471(4):462-81
references.pmid: 15022264
references.citation: Am J Physiol Regul Integr Comp Physiol. 2008 Jun;294(6):R1863-72
references.pmid: 18385465
references.citation: Am J Physiol Regul Integr Comp Physiol. 2003 Jul;285(1):R110-6
references.pmid: 12609814
references.citation: J Appl Physiol (1985). 2002 Aug;93(2):427-39
references.pmid: 12133847
references.citation: Prog Brain Res. 2006;152:11-26
references.pmid: 16198690
references.citation: J Comp Neurol. 2004 Nov 15;479(3):257-70
references.pmid: 15457502
references.citation: J Neurosci. 1994 Feb;14(2):667-96
references.pmid: 8301357
references.citation: J Appl Physiol (1985). 1992 Jul;73(1):96-100
references.pmid: 1506406
references.citation: J Physiol. 1999 Jun 1;517 ( Pt 2):477-94
references.pmid: 10332096
references.citation: Pharmacol Rev. 2010 Sep;62(3):405-96
references.pmid: 20716669
references.citation: J Physiol. 1995 Jan 1;482 ( Pt 1):53-68
references.pmid: 7730989
references.citation: Brain Res. 1988 Jul 5;455(1):187-91
references.pmid: 3416186
references.citation: J Comp Neurol. 2002 Mar 12;444(3):207-20
references.pmid: 11840475
references.citation: J Auton Nerv Syst. 2000 Apr 12;80(1-2):1-7
references.pmid: 10742533
references.citation: Nat Rev Neurosci. 2006 May;7(5):335-46
references.pmid: 16760914
references.citation: Neuroreport. 2004 Mar 1;15(3):431-6
references.pmid: 15094498
references.citation: J Auton Nerv Syst. 1990 Jul;30(3):209-20
references.pmid: 2172354
references.citation: Eur J Neurosci. 2008 Aug;28(3):428-46
references.pmid: 18702716
references.citation: Brain Res. 2003 Apr 25;970(1-2):35-46
references.pmid: 12706246
references.citation: Mol Psychiatry. 2006 Aug;11(8):737-47, 705
references.pmid: 16702973
references.citation: J Comp Neurol. 2005 Nov 28;492(4):477-94
references.pmid: 16228993
references.citation: Neuropharmacology. 2006 Sep;51(4):747-55
references.pmid: 16806304
references.citation: J Appl Physiol (1985). 2011 Dec;111(6):1854-62
references.pmid: 21979802
references.citation: Neurosci Lett. 1981 Sep 25;25(3):257-62
references.pmid: 6270602
references.citation: J Comp Neurol. 2004 May 17;473(1):73-85
references.pmid: 15067719
references.citation: J Physiol. 2010 Jan 1;588(Pt 1):93-9
references.pmid: 19822542
references.citation: Respir Physiol Neurobiol. 2010 Oct 31;173(3):256-63
references.pmid: 20226279
references.citation: J Comp Neurol. 2007 Aug 20;503(6):741-67
references.pmid: 17570127