Project 3: Normalization of Neuronal Excitability

项目摘要-项目3 临床和临床前数据都清楚地表明，OP诱发的癫痫持续状态(SE)的幸存者可以 出现持续性神经病理、自发性反复发作(SRS)和认知功能障碍。当前 急性OP中毒的标准护理(SOC)包括M受体拮抗剂阿托品、 与诸如氯解磷定(2-PAM)之类的肟结合，以重新激活乙酰胆碱酯酶，最后 苯二氮卓类药物可增加抑制性语气。然而，现在很明显，SOC预防SE或 以抵消OP引起的胆碱能风暴的下游后果，随着时间的推移迅速减少。 具体地说，立即使用阿托品和2-PAM治疗可以提高生存能力，但不能防止 过渡到东南区。一旦进入SE，苯二氮卓类药物中断癫痫发作并防止持续发作的可能性 细胞死亡迅速减少。同样清楚的是，随着急性中毒和治疗之间的间隔增加， 相应的慢性神经缺陷的严重程度也会增加。很可能在一次弥撒之后 伤亡事件，暴露在化学威胁剂下的平民的待遇将落在最佳水平之外 治疗窗口，增加他们发展为持续性SRS和认知障碍的可能性。 因此，显然有必要确定生物标记物，以确定那些具有最高风险的人 发展长期发病率，并超越现场急性OP中毒的管理， 并研究处理慢性神经后遗症的治疗策略，包括SRS和 认知功能障碍。在项目3中，我们将首先评估急性DFP中毒的自然历史。这将是 包括对整个过程中从深度和皮质电极记录的神经振荡的严格评估 在受伤后四个月，对SRS进行量化，并对两组标准的 认知结果(Y迷宫、新物体识别和语境恐惧条件作用)以及翻译 相关的触摸屏行为(评估记忆、执行功能和注意力)。然后我们将评估 四种候选治疗药物具有调节兴奋性、恢复振荡、减少癫痫发作和 提高认知能力。这些候选药物包括：(I)FDA批准的乳糖胺，它可以增强慢性病 电压门控钠通道(NAV)的失活；(Ii)FDA批准的利鲁唑，它阻断NAV，但也 增强小电导钙激活钾通道(KCA)和谷氨酰胺的活性 运输；(Iii)SKA-19，NAV阻滞剂和KCA激活剂的混合体；和(Iv)NS13001，相对选择性的KCA 激活剂。最后，我们将确定组合疗法的潜力，包括上述疗法之一 使用theta频率脑深部刺激以进一步管理慢性神经结局的候选人 与急性有机磷农药中毒有关。最终，项目3将揭示毒性的分子机制和 潜在地确定新的治疗目标以预防(通过紧急提供已确定的治疗)或治疗(通过 慢性分娩)破坏性的长期神经后遗症，包括SRS和认知功能障碍。

Project Summary – Project 3 Both clinical and preclinical data clearly demonstrate that survivors of OP-induced status epilepticus (SE) can develop persistent neuropathology, spontaneous recurring seizures (SRS) and cognitive dysfunction. Current standard-of-care (SOC) for acute OP intoxication includes the muscarinic receptor antagonist, atropine, combined with an oxime, such as pralidoxime chloride (2-PAM) to reactivate acetylcholinesterase and finally a benzodiazepine to increase inhibitory tone. However, it is now clear that the potential for SOC to prevent SE or to counteract the downstream consequences of the OP-induced cholinergic storm rapidly diminishes with time. Specifically, immediate treatment with atropine and 2-PAM can increase viability, but does not prevent a transition into SE. Once in SE, the potential for benzodiazepines to interrupt seizures and protect against ongoing cell death quickly declines. It is also clear that as the interval between acute intoxication and treatment increases, the severity of the corresponding chronic neurological deficits increases as well. It is likely that following a mass casualty event, treatment of civilians exposed to chemical threat agents is going to fall outside of the optimal therapeutic window, increasing the likelihood that they will develop persistent SRS and cognitive disorders. Therefore, there is a clear need to identify biological markers to identify those individuals with the highest risk of developing long-term morbidity and also to move beyond the management of acute OP intoxication in the field, and to investigate therapeutic strategies for managing chronic neurological sequelae, including SRS and cognitive dysfunction. In Project 3, we will first evaluate the natural history of acute DFP intoxication. This will include a rigorous assessment of neural oscillations recorded from depth and cortical electrodes over the course of four months following injury, the quantification of SRS and also evaluation of both a standard battery of cognitive outcomes (Y-maze, novel object recognition and contextual fear conditioning) and also translationally relevant touchscreen behaviors (that evaluate memory, executive function, and attention). We will then evaluate four therapeutic candidates for their potential to modulate excitability, restore oscillations, reduce seizures and improve cognition. These candidates include: (i) FDA-approved lacosamide, which enhances the slow inactivation of voltage-gated sodium channels (Nav); (ii) FDA-approved riluzole, which blocks Nav, but also enhances the activity of small-conductance calcium-activated potassium channels (KCa) and also glutamine transport; (iii) SKA-19, a mixed Nav blocker and KCa activator; and (iv) NS13001, a relatively selective KCa activator. Finally, we will determine the potential of combinatorial therapy including one of the above therapeutic candidates with theta frequency deep brain stimulation to further manage the chronic neurological outcomes associated with acute OP intoxication. Ultimately, Project 3 will uncover molecular mechanisms of toxicity and potentially identify novel therapeutic targets to prevent (with acute delivery of identified therapies) or treat (with chronic delivery) the devastating long-term neurological sequelae, including SRS and cognitive dysfunction.