Prolongation of the laryngeal chemoreflex after inhibition of the rostral ventral medulla in piglets: a role in SIDS?
نویسندگان
چکیده
We tested the hypothesis that inhibition of neurons within the rostral ventral medulla (RVM) would prolong the laryngeal chemoreflex (LCR), a putative stimulus in the sudden infant death syndrome (SIDS). We studied the LCR in 19 piglets, age 3-16 days, by injecting 0.05 ml of saline or water into the larynx during wakefulness, non-rapid eye movement (NREM) sleep, and REM sleep, before and after 1 or 10 mM muscimol dialysis in the RVM. Muscimol prolonged the LCR (P < 0.05), and the prolongation was greater when the LCR was stimulated with water compared with saline (P < 0.02). The LCR was longer during NREM sleep than during wakefulness and longest during REM sleep (REM compared with wakefulness). Muscimol had no effect on the likelihood of arousal from sleep after LCR stimulation. We conclude that the RVM provides a tonic facilitatory drive to ventilation that limits the duration of the LCR, and loss of this drive may contribute to the SIDS when combined with stimuli that inhibit respiration.
منابع مشابه
TRANSLATIONAL PHYSIOLOGY Unilateral microdialysis of gabazine in the dorsal medulla reverses thermal prolongation of the laryngeal chemoreflex in decerebrate piglets
Xia L, Damon T, Niblock MM, Bartlett D Jr, Leiter JC. Unilateral microdialysis of gabazine in the dorsal medulla reverses thermal prolongation of the laryngeal chemoreflex in decerebrate piglets. J Appl Physiol 103: 1864–1872, 2007. First published September 6, 2007; doi:10.1152/japplphysiol.00524.2007.—The laryngeal chemoreflex (LCR) is elicited by water in the larynx and leads to apnea and re...
متن کاملUnilateral microdialysis of gabazine in the dorsal medulla reverses thermal prolongation of the laryngeal chemoreflex in decerebrate piglets.
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Hyperthermia and reflex apnea may both contribute to sudden infant death syndrome (SIDS). Therefore, we investigated the effect of increased body temperature on the inhibition of breathing produced by water injected into the larynx, which elicits the laryngeal chemoreflex (LCR). We studied decerebrated, vagotomized, neonatal piglets aged 3-15 days. Blood pressure, end-tidal CO(2), body temperat...
متن کاملNeurochemistry and anatomy of the ventral medulla
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ورودعنوان ژورنال:
- Journal of applied physiology
دوره 94 5 شماره
صفحات -
تاریخ انتشار 2003