Mechanisms of EEG and Cardiovascular Arousal

在阻塞性睡眠呼吸暂停(OSA)中，患者在睡眠中反复失去主干运动张力，导致 呼吸道塌陷和呼吸暂停。这会导致缺氧、高碳酸血症和呼吸努力增加，直到 这是一种唤醒，恢复了主干道的通畅。脑电波唤醒导致睡眠碎片化 而自主神经的唤醒会导致交感神经音调增加，这可能会对长期有害 认知和心血管后果，但这些唤醒的机制尚不清楚。在项目中 1.我们推测臂旁核(PB)及邻近蓝前核内的谷氨酸能神经元 阻塞性睡眠呼吸暂停阻塞性睡眠呼吸暂停综合征患者的脑电和自主神经觉醒在脑区(PC)起关键作用。在……里面 具体目标1，我们将测试PB/PC中显示Fos激活的谷氨酸能神经元是否在 睡眠期间反复短暂的高碳酸血症投射到产生脑电的关键前脑靶点 觉醒(下丘脑、丘脑、基底前脑、杏仁核、前额叶皮质)和关键脑干靶点 通过逆行追踪结合Fos免疫组织化学和水泡产生自主神经唤醒 谷氨酸转运蛋白2(VGLUT2)原位杂交。在具体目标2和3中，我们确定了 分别在脑电和脑电中删除这些VGLUT2+PB/PC神经元亚群中的谷氨酸能传递 自主神经(心率、心电功率谱)觉醒。我们将通过使用VGLUT2条件基因敲除小鼠来实现这一点 携带Cre重组酶和绿色荧光蛋白(GFP)基因的腺相关病毒载体(/VAV)。我们将AAV-Cre/GFP注射到PB/PC，从PB/PC神经元亚群中删除VGLUT2的表达和谷氨酸传递，并将其与重复短暂接触二氧化碳时的EEG(觉醒持续时间，高频/高频脑电功率)和心电(HR，低频/高频心电功率)对觉醒的影响相关联。然后，我们将用GFP追踪受影响的PB/PC神经元的投射，并确定哪些靶点对所看到的变化至关重要。 这些研究将有助于破译导致OSA期间脑电和自主神经觉醒的大脑回路，并设计干预措施，将其认知和心血管后果降至最低。

In obstructive sleep apnea (OSA), patients repeatedly lose ainway motor tone during sleep, resulting in collapse of the airway and apnea. This results in hypoxia, hypercarbia, and increased respiratory effort, until there is an arousal in which the ainway patency is restored. The EEG arousal causes sleep fragmentation and the autonomic arousal causes increased sympathetic tone, which may have deleterious long term cognitive and cardiovascular consequences, but the mechanisms for these arousals are not know. In Project 1, we hypothesize that glutamatergic neurons in the parabrachial nucleus (PB) and adjacent precoeruleus region (PC) play a key role in causing EEG and autonomic arousals during obstructive sleep apnea OSA. In Specific Aim 1, we will test whether the glutamatergic neurons in the PB/PC that show Fos-activation during repeated brief episodes of hypercarbia during sleep project to key forebrain targets for producing EEG arousal (hypothalamus, thalamus, basal forebrain, amygdala, prefrontal cortex) and key brainstem targets for producing autonomic arousal, by combining retrograde tracing with Fos immunohistochemistry and vesicular glutamate transporter 2 (VGLUT2) in situ hybridization. In Specific Aims 2 and 3, we determine the effects of deleting glutamatergic transmission in subsets of these VGLUT2+ PB/PC neurons, respectively on EEG and autonomic (HR, ECG power spectrum) arousal. We will do this by using VGLUT2 conditional knockout mice and adeno-associated viral vectors (/VAV) containing the genes for Cre recombinase and Green Fluorescent Protein (GFP). We will inject the AAV-Cre/GFP into the PB/PC, deleting VGLUT2 expression and glutamate transmission from subsets of PB/PC neurons, and correlate this with the EEG (duration of arousal, high frequency/low frequency EEG power) and the ECG (HR, low frequency/high frequency ECG power) consequences on arousals during repeated brief C02 exposures. We will then trace the projections from the affected PB/PC neurons with GFP, and determine which targets are critical for the alterations that are seen. These studies will help in deciphering the brain circuitry causing EEG and autonomic arousals during OSA, and in designing interventions to minimize its cognitive and cardiovascular consequences.