The neural circuitry of seizure-induced apnea and SUDEP

癫痫发作引起的呼吸暂停和 SUDEP 的神经回路

• 批准号: 10719519
• 负责人: Ian Christopher Wenker
• 金额: $ 40.38万
• 依托单位: UNIVERSITY OF VIRGINIA
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-06-01 至 2028-05-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10719519
• 关键词: Acute; Address; Apnea; Benchmarking; Brain; Brain Mapping; Brain Stem; Breathing; Bypass; Cardiac; Cause of Death; Cell Nucleus; Cessation of life; Chromosome Mapping; Clonic Seizure; Data; Development; Electrophysiology (science); Elements; Epilepsy; Experimental Designs; FOXP2 gene; Failure; Generations; Genetic; Heart Arrest; In Vitro; Individual; Injections; Interruption; Maps; Midbrain structure; Modeling; Motor Seizures; Mus; Muscle; Mutant Strains Mice; Mutation; National Institute of Neurological Disorders and Stroke; Nerve Fibers; Neurons; Nodal; Patients; Pattern; Phase; Pontine structure; Prevention strategy; Prosencephalon; Recovery; Refractory; Research; Respiratory Failure; Risk Factors; Role; SCN8A gene; Seizures; Site; Slice; Structure; Sudden Death; Techniques; Testing; Tonic Seizures; Vagus nerve structure; Work; afferent nerve; hindbrain; in vivo; mouse model; mutant; neural; neural circuit; neuronal circuitry; neuronal excitability; novel; optogenetics; parabrachial nucleus; patch clamp; prevent; receptor; recruit; respiratory; selective expression; sudden unexpected death in epilepsy; ventilation; Acute; Address; Apnea; Benchmarking; Brain; Brain Mapping; Brain Stem; Breathing; Bypass; Cardiac; Cause of Death; Cell Nucleus; Cessation of life; Chromosome Mapping; Clonic Seizure; Data; Development; Electrophysiology (science); Elements; Epilepsy; Experimental Designs; FOXP2 gene; Failure; Generations; Genetic; Heart Arrest; In Vitro; Individual; Injections; Interruption; Maps; Midbrain structure; Modeling; Motor Seizures; Mus; Muscle; Mutant Strains Mice; Mutation; National Institute of Neurological Disorders and Stroke; Nerve Fibers; Neurons; Nodal; Patients; Pattern; Phase; Pontine structure; Prevention strategy; Prosencephalon; Recovery; Refractory; Research; Respiratory Failure; Risk Factors; Role; SCN8A gene; Seizures; Site; Slice; Structure; Sudden Death; Techniques; Testing; Tonic Seizures; Vagus nerve structure; Work; afferent nerve; hindbrain; in vivo; mouse model; mutant; neural; neural circuit; neuronal circuitry; neuronal excitability; novel; optogenetics; parabrachial nucleus; patch clamp; prevent; receptor; recruit; respiratory; selective expression; sudden unexpected death in epilepsy; ventilation

Sudden Unexpected Death in Epilepsy (SUDEP) accounts for up to 17% of all epilepsy-related deaths, and 50% for those refractory to treatment. There is increasing evidence that apnea (respiratory arrest) is the primary cause of death from SUDEP. We have shown in a number of mouse models - including PTZ injection, rapid kindling (prelim. data), and mouse models harboring Scn8a mutations identified from SUDEP patients - that sudden death is due to seizure-induced apnea (SIA) that occurs during tonic seizures, minutes prior to terminal asystole. As it pertains to this proposal, we have also made four other important observations: 1) artificial ventilation can prevent death and suppressed cardiac activity does not increase likelihood of fatality; 2) tonic contraction of breathing muscles represents a likely mechanism of SIA; 3) inhibition of cortical seizure activity does not impact SIA; and 4) inhibition of the inspiratory oscillator does not reduce apnea (prelim. data), suggesting seizure spread bypasses homeostatic elements of respiratory control circuitry. CENTRAL HYPOTHESIS: [AIM 1] Increased midbrain and pontine excitability is both necessary and sufficient to produce SIA, [AIM 2] the parabrachial/kölliker fuse (PB/KF) nucleus in the pons represents a key nodal point for SIA generation, and [AIM 3] that brainstem nuclei, like the PB/KF and PAG are recruited specifically during SIA, which we will explore using electrophysiology and genetic mapping. AIM 1: We have previously used chemogenetics to demonstrate that cortical ictal activity is not required for SIA and we now propose that hyperexcitability of the pons and midbrain drive SIA and SUDEP. We will use chemogenetics to inhibit different parts of the brainstem of Scn8a mutant mice to test their necessity for SIA and SUDEP. Additionally, we will test sufficiency of these regions by selectively expressing an Scn8a mutation that increases neuronal excitability. Using the rapid kindling model, we will also perform patch clamp recordings to test whether increased neuronal excitability in these regions occurs concurrently with the development of SIA. AIM 2: The parabrachial/kölliker fuse nucleus PB/KF in the Pons is a key nodal point for descending forebrain input and projects past the inspiratory oscillator, and is modulated by the vagus nerve. In this aim, we will photoinhibit the Foxp2-positive PB/KF neurons to regain normal breathing pattern during SIA, photostimulate P2ry1-positive vagal afferent nerve fibers to interrupt inspiration during SIA, and determine if PB/KF and Npy2r-positive vagal neuron photostimulation rescues postictal breathing in our PTZ SUDEP mouse model. AIM 3: We have demonstrated that tonic seizures with SIA and clonic seizures without SIA can occur in the very same mouse, both in Scn8a mutant and rapid kindling models (prelim. data) and that certain mid- and hindbrain structures are activated during SIA. We will determine the neuronal circuitry activated specifically during SIA and SUDEP using in vivo electrophysiology and TRAP2 identification of activated neurons.

癫痫（SUDEP）突然意外死亡占所有与癫痫有关的死亡的17％，并且 对于那些难治性治疗的人的50％。有越来越多的证据表明呼吸暂停（呼吸停滞）是 SUDEP死亡的主要原因。我们已经在许多鼠标模型中显示 - 包括PTZ注射， 快速点燃（PRELIM。DATA）以及带有SUDEP患者发现SCN8A突变的小鼠模型 - 突然死亡是由于癫痫发作诱发的呼吸暂停（SIA），在补品癫痫发作期间发生。 到终端方案。与该提案有关，我们还提出了另外四个重要的观察： 1）人工通气可以防止死亡并抑制心脏活动不会增加死亡的可能性； 2）呼吸肌肉的补品收缩代表了SIA的可能机制； 3）抑制皮质癫痫发作 活动不会影响SIA； 4）抑制灵感振荡器不会降低呼吸暂停（PRELIM。DATA）， 暗示癫痫发作旁绕过呼吸控制回路的稳态元件。中央 假设：[AIM 1]增加了中脑和蓬松刺激既需要又足够 生产SIA，[AIM 2] PONS中的Parabrachial/Köllliker保险丝（Pb/kf）核代表关键节点 SIA生成的点，[AIM 3]招募了脑干核，例如Pb/kF和PAG 目标1：我们 以前已经使用化学遗传学证明了SIA不需要皮质的发作活性 提议PON和Midbrain Drive SIA和SUDEP的过度兴奋。我们将使用化学遗传学 抑制SCN8A突变小鼠脑干的不同部分，以测试其对SIA和SUDEP的必要性。 此外，我们将通过选择性地表达增加的SCN8A突变来测试这些区域的安全性 神经元令人兴奋。使用快速点燃模型，我们还将执行补丁夹记录以测试是否 这些区域中神经元的刺激性增加与SIA的发展同时发生。目标2： PONS中的Parabrachial/KölllikerFuse fuse核PB/kF是前脑输入和 超越鼓舞人心的振荡器，并由迷走神经调节。在此目标中，我们将抑制 FOXP2阳性PB/KF神经元在SIA期间保持正常呼吸模式，光刺激P2RY1阳性 迷走神经纤维可在SIA期间中断灵感，并确定PB/KF和NPY2R阳性迷走神经 神经元光刺激挽救了我们的PTZ SUDEP小鼠模型中的邮政呼吸。目标3：我们有 证明在同一小鼠中可能会出现具有SIA和clonic癫痫发作的隆隆性癫痫发作， 在SCN8A突变体和快速点燃模型中 在SIA期间激活。我们将使用使用SIA和SUDEP在SIA期间专门激活的神经元电路 活体电生理学和活化神经元的TRAP2鉴定。