Understanding CNS Excitatory / Inhibitory Balance and the Sexually Dimorphic Role of System xc-

健康的大脑需要兴奋/抑制（E/I）平衡，E/I平衡的改变有助于神经和神经发育障碍和疾病（即中风，癫痫和自闭症）的病理生物学。需要更深入地了解调节生理E/I平衡的细胞和分子机制，以改善当前管理E/I扰动的临床策略。我们实验室的最新证据表明，异源二聚体质膜氨基酸胱氨酸/谷氨酸反向转运体，系统xc-（Sxc-），有助于维持体内神经元的E/I平衡。具体地说，我们发现，雄性和雌性Sxc- null小鼠（SLC 7a 11 sut/sut）表现出的行为过度兴奋表型急性全身给药的化学惊厥剂红藻氨酸后，与它们的野生型同窝仔。这种性别无关的过度兴奋表型伴随着性别依赖性的形态学变化，这些变化以前与网络兴奋性增加有关。这些观察结果导致了一个有趣的假设，将在Aim 1中充分探讨，即在幼稚SLC 7a 11 sut/sut小鼠中发现的形态学性别差异是性别非依赖性过度兴奋的基础，最终导致认知行为障碍。相比之下，红藻氨酸（用于诱导癫痫持续状态的亚急性范例）的更长时间的管理结果在雄性和雌性SLC 7a 11 sut/sut小鼠的行为低兴奋性，发生在性别匹配的SLC 7a 11 +/+（野生型）小鼠相反。因此，目的2调查是否，经过长时间的兴奋性突触后受体的性别无关的缩小发生在神经元的SLC 7a 11 sut/sut小鼠。杂合子小鼠的内部育种允许雄性和雌性SLC 7a 11 sut/sut和SLC 7a 11 +/+同窝仔用于每个目的。在这两个目标中，兴奋性的变化将通过体内EEG记录来检测，以测量多突触电脑活动的变化，并通过体外电生理学来确定相关的突触变化，这些突触变化是幼稚SLC 7a 11 sut/sut小鼠中过度兴奋表型的基础（目标1），以及KA范例完成时的低兴奋表型（目标2）。这些目标的成功完成将提供重要的机械信息的性二态性作用的SXC-在E/I的平衡和不平衡。奖学金培训计划包括严格的技术（电生理学、EEG无线电遥测、行为测试）和专业培训（口头/书面交流、统计分析、研究设计、指导），分别在锡拉丘兹大学和纽约州立大学上州医科大学的申办者和共同申办者的研究实验室进行，这些研究实验室遵守NINDS Rigor报告规定的政策和程序。在SU适当的和两所大学之间的丰富的，合作的神经科学研究环境将为候选人提供各种研究培训和资源，以及成功过渡到学术研究生涯所需的基本专业发展机会。

A healthy brain requires excitatory/inhibitory (E/I) balance and alterations in E/I balance contribute to the pathobiology of neurological and neurodevelopmental disorders and disease (i.e. stroke, epilepsy and autism). A deeper understanding of the cellular and molecular mechanisms regulating physiological E/I balance is needed to improve current clinical strategies for managing E/I perturbations. Recent evidence from our lab demonstrates that the heterodimeric plasma membrane amino acid cystine/glutamate antiporter, System xc- (Sxc-), contributes to the maintenance of neuronal E/I balance in vivo. Specifically, we find that both male and female Sxc- null mice (SLC7a11sut/sut) demonstrate a behavioral hyperexcitable phenotype upon acute systemic administration of the chemoconvulsant kainate, as compared to their wild-type littermates. This sex-independent hyperexcitable phenotype is accompanied by sex-dependent morphological changes that have been previously associated with increased network excitability. These observations led to the intriguing hypothesis, to be fully explored in Aim1, that the morphological sex differences found in naïve SLC7a11sut/sut mice underlie the sex-independent hyperexcitability, ultimately leading to cognitive behavioral impairment. In contrast, more prolonged administration of kainate (a subacute paradigm used to induce status epilepticus) results in behavioral hypoexcitability in both male and female SLC7a11sut/sut mice, the opposite from what occurs in sex-matched SLC7a11+/+ (wildtype) mice. Thus, Aim 2 investigates whether, after prolonged excitation, sex-independent downscaling of excitatory postsynaptic receptors occurs in neurons of SLC7a11sut/sut mice. In-house breeding of heterozygous mice allows both male and female SLC7a11sut/sut and SLC7a11+/+ littermates to be used in each aim. In both aims, changes in excitability will be detected by in vivo EEG recording, to measure changes in polysynaptic electrical brain activity, and in vitro electrophysiology, to identify the associated synaptic changes underlying the hyperexcitable phenotype in naïve SLC7a11sut/sut mice (Aim 1), and the hypoexcitable phenotype at completion of the KA-paradigm (Aim 2). Successful completion of these aims will provide important mechanistic information concerning the sexually dimorphic role of Sxc- in E/I balance and imbalance. The fellowship training plan includes rigorous technical (electrophysiology, EEG radiotelemetry, behavioral testing) and professional training (oral/written communication, statistical analysis, research design, mentorship) in the sponsor and co-sponsor’s research labs at Syracuse University and SUNY Upstate Medical University, respectively, that adheres to the policies and procedures laid down by the NINDS Rigor report. The rich, collaborative neuroscience research environment at SU proper and between the two universities will provide the candidate with varied research training and resources, and essential professional development opportunities needed for successful transition to an academic research career.