title: Hypoxia induces c-Fos protein expression in NMDA but not AMPA glutamate receptor labeled neurons within the nucleus tractus solitarii of the conscious rat.
abstract: Glutamatergic transmission within the nucleus tractus solitarii (nTS) is critical to full expression of hypoxia-induced cardiorespiratory responses in the rat. To further examine the role of N-methyl-D-aspartate (NMDA) and alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA) glutamate receptors in these responses, double-labeling studies of immunoreactivity for c-Fos protein and either NMDA (NR1) or AMPA (mGluR2/3) receptor expression were conducted in normoxic rats and in hypoxic rats receiving vehicle, MK801, or NBQX. Hypoxia markedly increased c-Fos immunoreactivity within nTS neurons which in the vast majority co-labeled for NMDA. Furthermore, MK801 markedly attenuated such responses. In contrast, co-localization of AMPA and c-Fos occurred in only a small proportion of neurons, and NBQX failed to modify hypoxia-induced c-Fos enhancements. These data suggest a predominant role for NMDA but not for AMPA glutamate receptors in nTS mediated components of the hypoxic response.
authors: Department of Pediatrics, Tulane University School of Medicine, New Orleans, LA 70112, USA. dgozal@tmcpop.tmc.tulane.edu
authors: D
authors: D
authors: Gozal
authors: Y D
authors: YD
authors: Xue
authors: N
authors: N
authors: Simakajornboon
mesh_terms: D000388:Air; D000595:Amino Acid Sequence; D000818:Animals; D015687:Cell Hypoxia / Q000502:physiology*; D003243:Consciousness; D016291:Dizocilpine Maleate / Q000494:pharmacology; D005786:Gene Expression Regulation / Q000187:drug effects; D008297:Male; D008969:Molecular Sequence Data; D009474:Neurons / Q000378:metabolism*; D016760:Proto-Oncogene Proteins c-fos / Q000096:biosynthesis*; D011810:Quinoxalines / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D018091:Receptors, AMPA / Q000378:metabolism*; D016194:Receptors, N-Methyl-D-Aspartate / Q000378:metabolism*; D017552:Solitary Nucleus / Q000166:cytology* / Q000378:metabolism
chemical_list: D016760:Proto-Oncogene Proteins c-fos; D011810:Quinoxalines; D018091:Receptors, AMPA; D016194:Receptors, N-Methyl-D-Aspartate; C062865:2,3-dioxo-6-nitro-7-sulfamoylbenzo(f)quinoxaline; D016291:Dizocilpine Maleate