Benzodiazepine treatment induced neuroplasticity

苯二氮卓类（BZ）是广泛用于治疗焦虑、失眠和癫痫发作的治疗药物， 作为精神分裂症和抑郁症的额外药物治疗。BZ结合并增强BZ的抑制活性。 GABA A型受体（GABAARs）。尽管BZ有效，但长期使用 严重受限于容忍、依赖和退缩。关于这一现象的机制， 神经适应性是BZ耐受性大脑状态的基础。慢性BZ治疗导致BZ减少 GABAAR的GABA活性增强，表明受体亚单位组成和/或功能的变化 在抑制性突触上此外，BZ治疗期间发生的神经可塑性也依赖于 兴奋性谷氨酸能N-甲基-D-天冬氨酸受体（NMDAR），与NMDAR共同给药 拮抗剂可阻止BZ耐受性。使用高通量定量蛋白质组学方法 研究BZ镇静耐受诱导的啮齿动物皮层变化，我们的数据首次显示， 关键兴奋性突触成分的显著上调。加上我们之前的研究表明， 持续的BZ暴露降低了BZ敏感的GABAAR的突触水平，这些发现产生了 中心假设：苯二氮卓类治疗减少苯敏感GABAAR亚型信号传导 同时增强兴奋性突触强度。拟议的研究利用了 新的光学方法和定量蛋白质组学，以解决关键的知识差距，如何延长BZ 在抑制性GABAAR和兴奋性NMDAR信号传导中诱导神经可塑性。两个独立且 提出了补充性的目的来测试BZ耐受性的这些机制组成部分。第一个目标将 使用定量质谱、电生理学、行为学和药理学方法来定义和 在功能上评估体内BZ治疗诱导的抑制性和兴奋性突触的变化， 啮齿动物皮层第二个目标将采用高分辨率成像技术和创新的光学 生物传感器BZ敏感GABAAR在体外和体内，结合遗传，生化和 电生理学方法鉴定BZ处理诱导的GABAAR翻译后修饰， 导致BZ快速解偶联和进展为BZ镇静耐受的细胞机制。这些 这些发现将为缓解或避免BZ的治疗方法的发展提供新的方向 宽容，解决重大未满足的公共卫生需求。

Benzodiazepines (BZs) are therapeutic drugs widely used to treat anxiety, insomnia and seizure disorders and as additional drug therapy in schizophrenia and depression. BZs bind and potentiate the inhibitory activity of specific subtypes of GABA type A receptors (GABAARs). Despite the efficacy of BZs, their prolonged use is severely limited by tolerance, dependence and withdrawal. Very little is mechanistically known about the neuroadaptations that underlie a BZ tolerant brain state. Chronic BZ treatment results in a decrease in BZ potentiation of GABA activity at GABAARs, suggesting changes in receptor subunit composition and/or function at inhibitory synapses. Furthermore, the neuroplasticity occurring during BZ treatment is also dependent on excitatory glutamatergic N-methyl-D-aspartate receptors (NMDAR), as co-administration of NMDAR antagonists can prevent BZ tolerance. Using a high throughput quantitative proteomic approach to investigate BZ sedative tolerance-induced changes in the rodent cortex our data show for the first time significant upregulation of key excitatory synapse components. Together with our prior work showing that sustained BZ exposure decreases synaptic levels of BZ sensitive GABAARs, these findings generated the central hypothesis: Benzodiazepine treatment reduces benzo-sensitive GABAAR subtype signaling concomitant with enhancing excitatory synapse strength. The proposed research capitalizes on the use of novel optical methods and quantitative proteomics to address the critical knowledge gap in how prolonged BZ use induces neuroplasticity in both inhibitory GABAAR and excitatory NMDAR signaling. Two independent and complementary Aims are proposed to test these mechanistic components of BZ tolerance. The first aim will use quantitative mass spectrometry, electrophysiology, behavioral and pharmacological methods to define and functionally assess in vivo BZ treatment induced changes in both inhibitory and excitatory synapses of the rodent cortex. The second aim will apply high resolution imaging techniques and an innovative optical biosensor for BZ sensitive GABAAR in vitro and in vivo, combined with genetic, biochemical and electrophysiological approaches to identify BZ treatment induced GABAAR post translational modifications and cellular mechanisms leading to rapid BZ uncoupling and the progression to BZ sedative tolerance. These findings will provide new directions for the development of therapeutic approaches to mitigate or avoid BZ tolerance, addressing a significant unmet public health need.