The upper airway and the sudden Infant Death Syndrome

描述(申请人提供)：尽管最近在预防方面取得了进展，但在美国，婴儿猝死综合症(SIDS)仍然是导致一个月至一岁婴儿死亡的最常见原因。一个令人震惊的流行病学发现是，在俯卧位发现的受害者比预期的要多，通常会把脸埋在被子里。鼓励婴儿仰卧睡觉的运动在几个国家导致了SID发病率的可喜下降，但体位的影响仍然是个谜。该项目将使用去大脑的新生仔猪来探索这样一种可能性，即俯卧睡眠的风险是由涉及上呼吸道的反射反应决定的，这些反应可能会因上呼吸道的二氧化碳(来自再次呼吸)、腹侧髓质的异常(在一些SID患者中有证据)或由于体温升高(有流行病学证据和一项有趣的小狗研究报告)而加剧。我们将研究每种情况对三种上呼吸道反射反应的影响：“潜水”反应、喉部化学反射和对上呼吸道阻塞的负荷补偿反射反应。我们的一般假设是，某些条件和刺激的组合会夸大呼吸的反射中断，可能导致SIDS的发病。

DESCRIPTION (provided by applicant): Despite recent progress in its prevention, the Sudden Infant Death Syndrome (SIDS) remains the most frequent cause of infant mortality between the ages of one month and one year in the United States. A striking epidemiological finding is that more victims than expected are found in the prone position, often with the face in the bedclothes. Campaigns to encourage putting infants to sleep on their backs have led to a gratifying reduction in the incidence of SIDS in several countries, yet the influence of posture remains mysterious. This project will use decerebrate neonatal piglets to explore the possibility that the risk of prone sleeping is determined by reflex responses involving the upper airway, and that these responses may be aggravated by CO2 in the upper airway (from re-breathing), by abnormalities of the ventral medulla (for which there is evidence in some SIDS victims), or from elevated body temperature (for which there is epidemiologic evidence and an intriguing report of a study in puppies). We will examine the influence of each of these conditions on three upper airway reflex responses: the "diving" response, the laryngeal chemo reflex and the load-compensating reflex response to upper airway obstruction. Our general hypothesis is that some combination of conditions and stimuli will exaggerate the reflex interruption of breathing, possibly contributing to the pathogenesis of SIDS.