Sleep Apnea and Hypoxic Neuronal Loss in Mice

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Sleep Apnea and Hypoxic Neuronal Loss in Mice

http://www.medicalnewstoday.com/articles/82224.php

Yan Zhu, Polina Fenik, Guanxia Zhan, Emilio Mazza, Max Kelz,

Aston- , and Sigrid C. Veasey

One of every 100 readers of this paragraph likely has sleep apnea.

The immediate concern with sleep apnea is daytime sleepiness because

of frequent nighttime sleep disruption. However, some studies have

suggested that the resulting cycles of hypoxia and reoxygenation may

cause longlasting neuronal damage. This week, Zhu et al. tested this

idea in rodents. The authors exposed adult male mice to longterm

intermittent hypoxia (LTIH) for 8 weeks.

This treatment consisted of O2 reduction from 21 to 10% for 5 s

every 90 s, which caused desaturation of oxyhemoglobin, not unlike

obstructive sleep apnea. Six months later, wakefulness was

irreversibly impaired compared with control mice. There was also

impaired activation of the immediate early gene c-fos upon waking in

dopamine neurons in the periaqueductal gray and noradrenergic

neurons in the locus ceruleus. Among wakeactive neurons, only

catecholamine neurons were diminished by LTIH. The NADPH oxidase

inhibitor apocynin prevented the loss.