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Neonatal maternal separation promotes respiratory instability during heat exposure in 12 days old rats: sex‐specific role of O 2 chemosensitivity
Author(s) -
Kinkead Richard,
Gulemetova Roumiana
Publication year - 2010
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.24.1_supplement.613.4
Subject(s) - apnea , respiratory system , hypoxic ventilatory response , medicine , peripheral chemoreceptors , ventilation (architecture) , plethysmograph , control of respiration , anesthesia , hypoxia (environmental) , physiology , endocrinology , chemoreceptor , chemistry , receptor , oxygen , mechanical engineering , organic chemistry , engineering
Neonatal maternal separation (NMS) interferes with respiratory control development. In adult male (but not female) rats, NMS increases the hypoxic ventilatory response (HVR) and augments respiratory instability during sleep. Because the effects of NMS on breathing prior to puberty are unknown, we tested whether NMS augments respiratory instability and the HVR in 12 days old rats. Pups subjected to NMS were placed in an incubator 3h/day from P3 to P12. Controls were undisturbed. Breathing and apnea index were measured in normoxia with plethysmography. Recording chamber was maintained either at 24°C or 29°C. Peripheral chemosensitivity was assessed by hypoxia (9% O 2 ; 5 min). Heat augmented both the HVR and apnea index. Although NMS had no effect on the HVR at either temperature it increased the apneas index in males only. Males: unlike controls, NMS pups showed no correlation between the HVR and apnea index, suggesting that mechanisms other than chemosensitivity contribute to respiratory instability in this group. Females: NMS pups (not controls) showed a significant correlation between HVR and apnea index. Thus unlike males, peripheral chemoreceptors contribute to respiratory instability in NMS females. At P12, the effects of NMS on breathing differ from those reported in adults; however, sex hormones already appear to play an important role in the manifestation of stress‐related respiratory control disorders.