A human mutation in Phox2b causes lack of CO2 chemosensitivity, fatal central apnea, and specific loss of parafacial neurons.
Breathing is maintained and controlled by a network of neurons in the brainstem that generate respiratory rhythm and provide regulatory input. Central chemoreception, the mechanism for CO(2) detection that provides an essential stimulatory input, is thought to involve neurons located near the medullary surface, whose nature is controversial. Good candidates are serotonergic medullary neurons and glutamatergic neurons in the parafacial region. Here, we show that mice bearing a mutation in Phox2b that causes congenital central hypoventilation syndrome in humans breathe irregularly, do not respond to an increase in CO(2), and die soon after birth from central apnea. They specifically lack Phox2b-expressing glutamatergic neurons located in the parafacial region, whereas other sites known or supposed to be involved in the control of breathing are anatomically normal. These data provide genetic evidence for the essential role of a specific population of medullary interneurons in driving proper breathing at birth and will be instrumental in understanding the etiopathology of congenital central hypoventilation syndrome.
Dubreuil
Véronique
V
Ecole Normale Supérieure, Département de Biologie, 75005 Paris, France.
Ramanantsoa
Nélina
N
Trochet
Delphine
D
Vaubourg
Vanessa
V
Amiel
Jeanne
J
Gallego
Jorge
J
Brunet
Jean-François
JF
Goridis
Christo
C
D000818:Animals; D002245:Carbon Dioxide / Q000378:metabolism*; D018398:Homeodomain Proteins / Q000235:genetics* / Q000378:metabolism*; D006801:Humans; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D009154:Mutation / Q000235:genetics; D009422:Nervous System Diseases / Q000235:genetics / Q000378:metabolism* / Q000473:pathology*; D012680:Sensitivity and Specificity; D020182:Sleep Apnea, Central / Q000235:genetics / Q000378:metabolism* / Q000473:pathology* / Q000503:physiopathology; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism*
D018398:Homeodomain Proteins; C109220:NBPhox protein; D014157:Transcription Factors; D002245:Carbon Dioxide