title: Intracellular acidosis and pH regulation in central respiratory chemoreceptors.
abstract: Dysfunctions of brainstem regions responsible for central CO2 chemoreception have been proposed as an underlying pathophysiology of Sudden Infant Death Syndrome (SIDS). We recorded respiratory motor output and intracellular pH (pHi) from chemosensitive neurons in an in vitro tadpole brainstem during normocapnia and hypercapnia. Flash photolysis of the H+ donor nitrobenzaldehyde was used to induce focal decreases in pHi alone. Hypercapnia and flash photolysis significantly decreased pHi from normocapnia. In addition, chemoreceptors did not regulate pHi during hypercapnia, but demonstrated significant pHi recovery when only pHi was reduced by flash photolysis. Respiration was stimulated by decreases in pHi (hypercapnia and flash photolysis) by decreases in burst cycle. These data represent our ability to load the brainstem with nitrobenzaldehyde without disrupting the respiration, to quantify changes in chemoreceptor pHi recovery, and to provide insights regarding mechanisms of human health conditions with racial/ethnic health disparities such as SIDS and Apnea of Prematurity (AOP).
authors.affiliation: Department of Biology, The University of Texas at San Antonio,1 UTSA Circle, San Antonio, TX 78249, USA.
authors.forename: C R Marutha
authors.initials: CR
authors.lastname: Ravindran
authors.forename: James N
authors.initials: JN
authors.lastname: Bayne
authors.forename: Sara C
authors.initials: SC
authors.lastname: Bravo
authors.forename: Theo
authors.initials: T
authors.lastname: Busby
authors.forename: Charles N
authors.initials: CN
authors.lastname: Crain
authors.forename: John A
authors.initials: JA
authors.lastname: Escobedo
authors.forename: Kenneth
authors.initials: K
authors.lastname: Gresham
authors.forename: Brian J
authors.initials: BJ
authors.lastname: O'Grady
authors.forename: Lourdes
authors.initials: L
authors.lastname: Rios
authors.forename: Shashwata
authors.initials: S
authors.lastname: Roy
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Gdovin
mesh_terms: D000142:Acidosis, Respiratory / Q000503:physiopathology*; D000818:Animals; D001933:Brain Stem / Q000502:physiology / Q000503:physiopathology*; D002628:Chemoreceptor Cells / Q000502:physiology*; D054625:Healthcare Disparities; D006801:Humans; D006863:Hydrogen-Ion Concentration; D006935:Hypercapnia / Q000503:physiopathology*; D007223:Infant; D007814:Larva; D010782:Photolysis; D012119:Respiration
references.citation: Am J Respir Crit Care Med. 2002 Dec 15;166(12 Pt 1):1530-1
references.pmid: 12471066
references.citation: Anat Rec. 1946 Jan;94:7-13
references.pmid: 21013391
references.citation: Ann N Y Acad Sci. 1988;533:13-30
references.pmid: 3048169
references.citation: N Engl J Med. 2009 Aug 20;361(8):795-805
references.pmid: 19692691
references.citation: Respir Physiol Neurobiol. 2002 Nov 19;133(3):277-82
references.pmid: 12425975
references.citation: Eur J Pediatr. 2011 Sep;170(9):1097-105
references.pmid: 21301866
references.citation: Respir Physiol Neurobiol. 2005 Nov 15;149(1-3):165-79
references.pmid: 15876557
references.citation: Am J Physiol. 1996 Oct;271(4 Pt 1):C1146-56
references.pmid: 8897820
references.citation: Am J Physiol Regul Integr Comp Physiol. 2000 Aug;279(2):R414-23
references.pmid: 10938227
references.citation: Curr Opin Neurobiol. 1995 Dec;5(6):778-85
references.pmid: 8805408
references.citation: Proc Natl Acad Sci U S A. 1966 Jan;55(1):134-41
references.pmid: 5220862
references.citation: Comp Biochem Physiol A Mol Integr Physiol. 1999 Nov;124(3):275-86
references.pmid: 10665380
references.citation: Am J Physiol Cell Physiol. 2003 Jan;284(1):C145-55
references.pmid: 12388081
references.citation: Comp Biochem Physiol A Mol Integr Physiol. 2001 Sep;130(2):207-18
references.pmid: 11544068
references.citation: Natl Vital Stat Rep. 2010 Apr 30;58(17):1-31
references.pmid: 20815136
references.citation: N Engl J Med. 1977 Oct 6;297(14):747-50
references.pmid: 895805
references.citation: Respir Physiol. 2001 Dec;129(1-2):37-56
references.pmid: 11738645
references.citation: J Exp Biol. 1997;200(Pt 15):2063-72
references.pmid: 9319973
references.citation: Biol Neonate. 1994;65(3-4):194-7
references.pmid: 8038282
references.citation: Neurosci Lett. 2005 Apr 29;379(1):27-31
references.pmid: 15814193
references.citation: Respir Physiol. 1997 Jun;108(3):205-13
references.pmid: 9241689
references.citation: Am J Physiol Regul Integr Comp Physiol. 2008 Sep;295(3):R922-34
references.pmid: 18596110
references.citation: J Appl Physiol (1985). 2002 Sep;93(3):936-46
references.pmid: 12183489
references.citation: Respir Physiol. 1998 Aug;113(2):135-46
references.pmid: 9832232
references.citation: Am J Physiol Regul Integr Comp Physiol. 2001 Dec;281(6):R1940-51
references.pmid: 11705781
references.citation: NCHS Data Brief. 2009 Nov;(23):1-8
references.pmid: 19887034
references.citation: Am J Physiol Regul Integr Comp Physiol. 2003 Dec;285(6):R1461-72
references.pmid: 14615406
references.citation: Am J Physiol Regul Integr Comp Physiol. 2007 Apr;292(4):R1621-31
references.pmid: 17138726
references.citation: J Neuropathol Exp Neurol. 2000 May;59(5):377-84
references.pmid: 10888367
references.citation: Am J Physiol. 1996 Oct;271(4 Pt 1):C1131-45
references.pmid: 8897819
references.citation: Biochemistry. 1979 May 29;18(11):2210-8
references.pmid: 36128
references.citation: Science. 2008 Jul 4;321(5885):130-3
references.pmid: 18599790
references.citation: J Exp Zool A Comp Exp Biol. 2006 Apr 1;305(4):335-47
references.pmid: 16493648
references.citation: JAMA. 2006 Nov 1;296(17):2124-32
references.pmid: 17077377
references.citation: Natl Vital Stat Rep. 2010 May;58(19):1-19
references.pmid: 25075874
references.citation: J Appl Physiol (1985). 2003 Mar;94(3):1204-12
references.pmid: 12571143
references.citation: J Physiol. 2002 Jun 1;541(Pt 2):493-509
references.pmid: 12042354
references.citation: J Physiol. 1996 Apr 15;492 ( Pt 2):545-58
references.pmid: 9019549
references.citation: J Physiol. 2004 Apr 1;556(Pt 1):235-53
references.pmid: 14724193
references.citation: Respir Physiol. 1987 Dec;70(3):377-90
references.pmid: 3120266
references.citation: Nat Rev Neurosci. 2004 Jun;5(6):449-61
references.pmid: 15152195
references.citation: Pediatr Res. 2006 Apr;59(4 Pt 1):519-24
references.pmid: 16549522