Center for Sleep and Health Research, University of Illinois Chicago, 845 S. Damen Ave (MC 802), Room 750, Chicago, IL, 60612, United States.
Office of Research Facilitation, University of Illinois Chicago, 845 S. Damen Ave (MC 802), Room 615, Chicago, IL, 60612, United States.
Respir Physiol Neurobiol. 2021 Jun;288:103653. doi: 10.1016/j.resp.2021.103653. Epub 2021 Mar 11.
To determine how partial lesioning of the pedunculopontine nucleus (PPT) affects sleep, breathing, and blood pressure in rats, ibotenic acid (IBO) was injected bilaterally into the PPT. Sham-injected (saline) and IBO-lesioned rats were first studied under normoxic conditions (40 recordings were obtained from 15 rats, with each recording lasting for 6 daytime hours). Rats were then exposed to intermittent hypoxia for 4 ± 2 days (51 recordings from 12 rats, each lasting 6 daytime hours). The intermittent hypoxia protocol involved an oxygen decline lasting 35 s (to a nadir of 10 %) followed by a 50 s increase to normoxia. The IBO caused an estimated 53 % reduction in PPT neurons. When normoxic, IBO-lesioned rats had remarkedly normal sleep architecture, respiratory rates, and mean arterial pressure. The exposure to intermittent hypoxia evoked tachypnea in both the IBO-lesioned and sham-injected rats. When intermittently hypoxic, IBO-lesioned rats demonstrated a significant reduction in the duration of rapid eye movement (REM) sleep. We conclude that partial lesions of the PPT do not disrupt cardiorespiratory activities, but a reduction in PPT neurons impairs the ability to sustain REM sleep under hypoxic conditions.
为了确定 pedunculopontine 核（PPT）的部分损伤如何影响大鼠的睡眠、呼吸和血压，将鹅膏蕈氨酸（IBO）双侧注入 PPT。首先在常氧条件下研究假注射（盐水）和 IBO 损伤大鼠（从 15 只大鼠中获得 40 个记录，每个记录持续 6 个白天小时）。然后，大鼠暴露于间歇性缺氧 4 ± 2 天（从 12 只大鼠中获得 51 个记录，每个记录持续 6 个白天小时）。间歇性缺氧方案涉及持续 35 s 的氧气下降（降至 10%的最低点），然后增加 50 s 至常氧。IBO 导致 PPT 神经元估计减少 53%。在常氧时，IBO 损伤大鼠的睡眠结构、呼吸频率和平均动脉压明显正常。间歇性缺氧会引起 IBO 损伤和假注射大鼠的呼吸急促。当间歇性缺氧时，IBO 损伤大鼠的快速眼动（REM）睡眠时间明显缩短。我们的结论是，PPT 的部分损伤不会破坏心肺活动，但 PPT 神经元的减少会削弱在缺氧条件下维持 REM 睡眠的能力。
