title: Ionic mechanisms of central CO(2) chemosensitivity.
abstract: A comparative analysis of chemosensory systems in invertebrates and vertebrates reveals that different animals use similar strategies when sensing CO(2) to control respiration. A variety of animals possess neurons that respond to changes in pH. These respiratory chemoreceptor neurons seem to rely largely on pH-dependent inhibition of potassium channels, but the channels do not appear to be uniquely adapted to detect pH. The 'chemosensory' potassium channels identified thus far are widely distributed, common potassium channels. The pH-sensitivity is a common feature of the channels whether the channels are in chemosensory neurons or not. Thus, the pattern of synaptic connectivity and the mix of potassium channels expressed seem to determine whether a neuron is chemosensory or not, rather than any special adaptation of a channel for pH-sensitivity. Moreover, there are often multiple pH-sensitive channels in each chemosensory neuron. These ionic mechanisms may, however, be only part of the chemosensory process, and pH-dependent modulation of synaptic activity seems to contribute to central chemosensitivity as well. In addition, the exploration of the mechanisms of pH-dependent modulation of ion channel activity in chemosensory cells is incomplete: additional mechanisms of pH modulation of channel activity may be found, and addition conductances, other than potassium channels, may participate in the chemosensory process.
authors.affiliation: Department of Physiology, Dartmouth Medical School, Lebanon, NH 03756, USA.
authors.forename: Mykyta M
authors.initials: MM
authors.lastname: Chernov
authors.forename: Joseph S
authors.initials: JS
authors.lastname: Erlichman
authors.forename: J C
authors.initials: JC
authors.lastname: Leiter
mesh_terms: D000818:Animals; D001921:Brain / Q000166:cytology / Q000502:physiology*; D002245:Carbon Dioxide / Q000378:metabolism*; D002628:Chemoreceptor Cells / Q000166:cytology / Q000378:metabolism*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007473:Ion Channels / Q000378:metabolism*; D009474:Neurons / Q000166:cytology / Q000378:metabolism; D012143:Respiratory Physiological Phenomena
chemical_list: D007473:Ion Channels; D002245:Carbon Dioxide
references.citation: Proc Natl Acad Sci U S A. 2007 Jan 9;104(2):666-71
references.pmid: 17197424
references.citation: Am J Physiol Cell Physiol. 2007 Jan;292(1):C278-91
references.pmid: 16928773
references.citation: J Physiol. 1982 Nov;332:1-24
references.pmid: 6818338
references.citation: Proc Natl Acad Sci U S A. 2010 Feb 2;107(5):2325-30
references.pmid: 20133877
references.citation: Respir Physiol Neurobiol. 2009 Mar 31;166(1):13-5
references.pmid: 19444986
references.citation: Neuron. 1995 Nov;15(5):1157-68
references.pmid: 7576658
references.citation: J Appl Physiol (1985). 2010 Jun;108(6):1803-11
references.pmid: 20110540
references.citation: Am J Physiol Cell Physiol. 2007 Jan;292(1):C292-304
references.pmid: 16928774
references.citation: Respir Physiol. 1993 Sep;93(3):347-63
references.pmid: 8305038
references.citation: J Neurosci. 2008 Aug 27;28(35):8844-50
references.pmid: 18753386
references.citation: Nat Neurosci. 2004 Dec;7(12):1360-9
references.pmid: 15558061
references.citation: J Neurophysiol. 1995 Mar;73(3):933-44
references.pmid: 7608778
references.citation: J Appl Physiol (1985). 1993 Jul;75(1):5-14
references.pmid: 8376301
references.citation: J Neurosci. 2002 Feb 15;22(4):1256-65
references.pmid: 11850453
references.citation: J Physiol. 2006 Apr 15;572(Pt 2):525-37
references.pmid: 16469786
references.citation: Am J Physiol Regul Integr Comp Physiol. 2004 Feb;286(2):R289-302
references.pmid: 14525723
references.citation: Nat Genet. 2003 Apr;33(4):459-61
references.pmid: 12640453
references.citation: J Appl Physiol (1985). 2001 Apr;90(4):1247-57
references.pmid: 11247921
references.citation: Brain Res. 1989 Apr 24;485(2):285-93
references.pmid: 2720414
references.citation: J Neurosci. 2007 Dec 19;27(51):14049-58
references.pmid: 18094244
references.citation: J Comp Neurol. 2009 Nov 1;517(1):69-86
references.pmid: 19711410
references.citation: J Appl Physiol (1985). 1996 Jan;80(1):108-15
references.pmid: 8847290
references.citation: Am Rev Respir Dis. 1975 Aug;112(2):165-72
references.pmid: 239616
references.citation: Am J Physiol. 1997 Jul;273(1 Pt 2):R433-41
references.pmid: 9249582
references.citation: Proc Natl Acad Sci U S A. 2008 Jan 22;105(3):1067-72
references.pmid: 18198276
references.citation: J Physiol. 2002 May 1;540(Pt 3):951-70
references.pmid: 11986382
references.citation: Respir Physiol Neurobiol. 2008 Dec 10;164(1-2):49-54
references.pmid: 18675942
references.citation: Respir Physiol. 1994 Feb;95(2):209-26
references.pmid: 8191042
references.citation: Annu Rev Neurosci. 2003;26:239-66
references.pmid: 12598679
references.citation: Respir Physiol. 1972 Mar;14(1):219-36
references.pmid: 4537783
references.citation: Exp Brain Res. 1989;76(3):656-61
references.pmid: 2507342
references.citation: Am J Physiol. 1986 Aug;251(2 Pt 2):R197-213
references.pmid: 3017133
references.citation: J Neurosci. 2006 Oct 4;26(40):10305-14
references.pmid: 17021186
references.citation: J Physiol. 2002 Jun 1;541(Pt 2):493-509
references.pmid: 12042354
references.citation: Nature. 2007 Jan 4;445(7123):86-90
references.pmid: 17167414
references.citation: Development. 2000 Apr;127(7):1349-58
references.pmid: 10704382
references.citation: Am J Physiol Regul Integr Comp Physiol. 2000 Aug;279(2):R414-23
references.pmid: 10938227
references.citation: Proc Natl Acad Sci U S A. 2007 Feb 27;104(9):3574-8
references.pmid: 17360684
references.citation: J Chem Ecol. 2004 Jun;30(6):1285-8
references.pmid: 15303329
references.citation: J Neurosci. 2008 Nov 26;28(48):12845-50
references.pmid: 19036978
references.citation: Am J Physiol. 1998 Oct;275(4):R1152-63
references.pmid: 9756546
references.citation: J Appl Physiol (1985). 2008 Jul;105(1):83-90
references.pmid: 18450988
references.citation: J Neurosci. 2007 Dec 19;27(51):14128-38
references.pmid: 18094252
references.citation: Am J Physiol Cell Physiol. 2003 Jan;284(1):C145-55
references.pmid: 12388081
references.citation: J Neurophysiol. 2009 Sep;102(3):1577-90
references.pmid: 19553484