Premium
Orexin is necessary both for hypercapnic ventilatory responses during awake state and for prevention of sleep apneas
Author(s) -
Nakamura Akira,
Zhang Wei,
Yanagisawa Masashi,
Fukuda Yasuichiro,
Kuwaki Tomoyuki
Publication year - 2007
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.21.6.a921
Subject(s) - wakefulness , orexin , ventilation (architecture) , medicine , anesthesia , sleep and breathing , vigilance (psychology) , non rapid eye movement sleep , slow wave sleep , endocrinology , control of respiration , electroencephalography , respiratory system , neuroscience , psychology , neuropeptide , physics , receptor , thermodynamics
We examined whether intrinsic orexin participates in the control of breathing in a vigilance state‐dependent manner. Ventilation was recorded together with electroencephalography and electromyography for 6 hrs during the daytime in prepro‐orexin knockout mice (ORX‐KO) and wild‐type (WT) littermates. Respiratory parameters were separately determined during quiet wakefulness (QW), slow wave sleep (SWS), or rapid eye movement (REM) sleep. Basal ventilation was normal in ORX‐KO, irrespective of vigilance states. Hypercapnic ventilatory response during QW in ORX‐KO (0.19±0.01 (mL/min/g, body weight)/% CO2) was significantly smaller than that in WT mice (0.38±0.04 (mL/min/g, body weight)/% CO2) whereas the responses during SWS and REM in ORX‐KO were comparable to those in WT mice. Hypoxic responses during wake and sleep periods were not different between the genotypes. Spontaneous but not post‐sigh sleep apneas were more frequent in ORX‐KO than in WT littermates during both SWS and REM sleep. We concluded that orexin plays a crucial role both in CO2‐sensitivity during wakefulness and in preservation of ventilation stability during sleep.