O2 Sensing Mechanisms and Development

Type I cell depolarization appears to be a critical step in O2 transduction and therefore is a major potential site for maturational changes. Type I cells in vitro (37) and in situ depolarize in response to hypoxia and, in the absence of a type I cell depolarization, hypoxia does not induce catecholamine secretion from the carotid 

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In every species studied to date, the carotid chemoreceptor response to hypoxia increases with postnatal age. In in vitro carotid body preparations, the peak nerve discharge in response to a potent hypoxia stimulus increases about fourfold in neonatal rats during the first month, with most of that change occurring by 2 weeks (10,12,45) (Fig. 2). Similar patterns of postnatal maturation of carotid sinus nerve 

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