Task2 potassium channels set central respiratory CO2 and O2 sensitivity.
Proc Natl Acad Sci U S A
; 107(5): 2325-30, 2010 Feb 02.
Article
em En
| MEDLINE
| ID: mdl-20133877
ABSTRACT
Task2 K(+) channel expression in the central nervous system is surprisingly restricted to a few brainstem nuclei, including the retrotrapezoid (RTN) region. All Task2-positive RTN neurons were lost in mice bearing a Phox2b mutation that causes the human congenital central hypoventilation syndrome. In plethysmography, Task2(-/-) mice showed disturbed chemosensory function with hypersensitivity to low CO(2) concentrations, leading to hyperventilation. Task2 probably is needed to stabilize the membrane potential of chemoreceptive cells. In addition, Task2(-/-) mice lost the long-term hypoxia-induced respiratory decrease whereas the acute carotid-body-mediated increase was maintained. The lack of anoxia-induced respiratory depression in the isolated brainstem-spinal cord preparation suggested a central origin of the phenotype. Task2 activation by reactive oxygen species generated during hypoxia could silence RTN neurons, thus contributing to respiratory depression. These data identify Task2 as a determinant of central O(2) chemoreception and demonstrate that this phenomenon is due to the activity of a small number of neurons located at the ventral medullary surface.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Oxigênio
/
Centro Respiratório
/
Dióxido de Carbono
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Canais de Potássio de Domínios Poros em Tandem
Tipo de estudo:
Diagnostic_studies
/
Etiology_studies
/
Prognostic_studies
Limite:
Animals
/
Female
/
Humans
/
Pregnancy
Idioma:
En
Revista:
Proc Natl Acad Sci U S A
Ano de publicação:
2010
Tipo de documento:
Article
País de afiliação:
França