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Enhancement of the hypoxic ventilatory reponse in adult rats subjected to neonatal maternal separation is not affected by sleep‐wake states
Author(s) -
Kinkead Richard,
Montandon Gaspard,
Lajeunesse Yves,
Bairam Aida,
Horner Richard
Publication year - 2008
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.22.1_supplement.1172.4
Subject(s) - wakefulness , anesthesia , medicine , sleep (system call) , respiratory system , arousal , control of respiration , ventilation (architecture) , hypoxia (environmental) , hypoxic ventilatory response , psychology , electroencephalography , oxygen , chemistry , neuroscience , mechanical engineering , organic chemistry , psychiatry , computer science , engineering , operating system
Neonatal maternal separation (NMS) disrupts respiratory control development. In the awake male rat, the hypoxic ventilatory response of adults previously subjected to NMS is ~25% greater than controls (Genest et al., 2004; 2007). Because changes in arousal state affect respiratory control, we tested the hypothesis that NMS‐related enhancement of the hypoxic ventilatory response occurs during sleep also. Experiments were performed on two groups of rats (n = 5 per group): Pups subjected to NMS were placed in an incubator 3h/day for 10 consecutive days (P3 to P12). Controls were undisturbed. Rats were then reared normally until adulthood (8 – 10 weeks) when EEG and neck EMG electrodes were implanted for sleep‐wake state monitoring by telemetry. Following recovery (14 days) baseline ventilatory activity was measured using plethysmography for 5 h. During each sleep‐wake state, rats were exposed to a brief hypoxic period (12% O 2 for 90 sec). Sleep‐wake states were scored visually. Minute ventilation changed across sleep‐wake states (p = 0.03). The hypoxic ventilatory response of NMS rats was greater than controls during wakefulness, REM, and non‐REM sleep (34, 47 and 53%, respectively; p ≤ 0.05). Since excessive hypoxic ventilatory response can lead to respiratory instability during sleep, these data suggest that early life stress exposure could predispose to respiratory disease in the adult. Supported by the CIHR.