Pediatric seizures: role of IP3R Ca2+ release channels

产前酒精暴露(PAE)后戒酒通常与全身性补药有关- 婴幼儿阵挛发作(GTC)和癫痫。我们的长期目标是了解钙离子是如何 信号可用于预防和治疗PAE相关的癫痫发作。我们最近开发了一种GTCSs大鼠模型 在PAE后戒酒后，观察到P7-P28和P7-P7-GTCS患病率增加 产后雌雄各35只。在这个模型中，新生下丘(IC)神经元表现为： I)增加出生后阶段的钙依赖的放电和ii)增加三磷酸肌醇的钙释放 在出生前和出生后，IC内的受体(IP3R)钙池均增加。建议进行的实验 这里旨在确定三个IP3R亚型-IP3R1、IP3R2和IP3R3对 妊娠中期单次PAE发作后戒酒后的GTCS易感性 制定新的具体办法的具体目标。我们在这项提案中的目标是调查 细胞内IP3R钙离子池中钙离子释放在酒精引起的神经元超兴奋性中的作用 妊娠中期PAE后停药。我们的工作假设是戒酒后 妊娠中期的PAE可上调IP3R钙池，导致钙释放增加，进而 有助于IC神经元的过度兴奋和癫痫敏感性的增加。为了验证我们的中心假设， 我们的实验将结合钙离子成像与电生理学、分子遗传学和药理学。这个 研究提案试图解决四个问题：i)细胞内IP3R钙池中的钙是如何释放的 产后P35雌雄大鼠的IC神经元是否发生改变？II)钙离子释放的抑制是如何 IP3R钙池抑制产后P35雌性和孕期酒精暴露大鼠的IC神经元放电 在E18？3)酒精戒断对大鼠孤束核IP3R基因和蛋白表达的影响 产后PAE P35雌雄产后大鼠？以及IV)抑制IC中的IP3R如何抑制 产后PAE P28和P35的GTCS。总体影响：非仿制抗惊厥药 在药物治疗方面，对于PAE后与酒精戒断相关的儿童癫痫，没有特定的治疗方法。通过 揭示IP3R门控钙释放机制异常在儿童酒精后癫痫发作中的作用 在PAE后停药，我们将增加对这些渠道作为潜在治疗靶点的理解 处理与PAE相关的癫痫。

Alcohol withdrawal following prenatal alcohol exposure (PAE) is frequently associated with generalized tonic- clonic seizures (GTCS) and epilepsy in infants and young children. Our long-term goal is to understand how Ca2+ signaling can be used to prevent and treat PAE-related seizures. We recently developed a rat model of GTCSs following alcohol withdrawal after PAE, in which increased GTCS prevalence was observed in P7-P28 and P7- P35 female and male postpartum rats, respectively. In this model, neonate inferior colliculus (IC) neurons exhibit: i) increased Ca2+-dependent firing in postnatal stage and ii) increased Ca2+ release from inositol triphosphate receptor (IP3R) Ca2+ pools is increased in the IC in both pre-and postnatal stages. The experiments proposed here are designed to determine the precise contribution of three IP3R subtypes—IP3R1, IP3R2 and IP3R3 to GTCS susceptibility following alcohol withdrawal after a single PAE episode during the 2nd trimester, proving specific targets for developing new specific approaches. Our objective in this proposal is to investigate the role of Ca2+ release from intracellular IP3R Ca2+ pools in IC neuronal hyperexcitability in response to alcohol withdrawal after PAE in the 2nd trimester of gestation. Our working hypothesis is that alcohol withdrawal following PAE during the 2nd trimester PAE upregulates IP3R Ca2+ pools resulting in elevated Ca2+ release, which in turn contribute to IC neuronal hyperexcitability and increased seizure susceptibility. To test our central hypothesis, our experiments will combine Ca2+ imaging with electrophysiology, molecular genetics, and pharmacology. The research proposal seeks to address four questions: i) how does Ca2+ release from intracellular IP3R Ca2+ pools is altered in IC neurons of postpartum P35 female and male rats? ii) how does inhibition of Ca2+ release from IP3R Ca2+ pools suppressed IC neuronal firing in postpartum P35 female and rats prenatally exposed to alcohol at E18? iii) how does alcohol withdrawal following PAE alter IP3R mRNA and protein expression in the IC of postpartum PAE P35 female and male postpartum rats? and iv) how does inhibition of IP3R in the IC suppresses GTCS in postpartum PAE P28 and P35, respectively. Overall Impact: Other than generic anticonvulsant medication, there is no specific therapy for pediatric seizures related to alcohol withdrawal after PAE. By revealing how aberrant IP3R-gated Ca2+ release mechanisms contribute to pediatric seizures following alcohol withdrawal after PAE, we will increase understanding of these channels as potential therapeutic targets for managing PAE-related seizures.