Effects of ICP elevation on NeuN Negative Membrane Disrupted Neurons

弥漫性创伤性脑损伤(TBI)与导致长期损伤的各种病理因素有关， 包括创伤后头痛(PTH)，尤其是偏头痛。在以下情况下，创伤性脑损伤的结果会更差 合并颅内压升高。F99工作的目标是阐明 机制(S)，这可能归因于颅脑损伤的病理和颅内压介导的弥漫性病理。这个 K00的目标是研究偏头痛的细胞和分子机制，以便成为研究人员 甲状旁腺素在颅脑损伤中的作用。一种病理，神经细胞膜破裂，已被证明是在脑外伤后急剧诱导的。 然而，我最初的研究表明，神经细胞膜的破裂可以持续到急性时间框架之后。 在脑外伤后持续数周。此外，数据表明，有一小部分皮质神经元具有这种功能 不表达NeuN，膜被破坏。对于其他损伤，Neun负面(Neun-)演示文稿 预示着回归到未成熟的神经元表型。如果受损的神经元正在恢复为未成熟的 表型，那么这可能是一种代偿机制，所以识别这些也是膜的神经元 破坏可能为膜破坏的分子机制提供更多的洞察。目标1a)是 应用脑室注射技术研究膜损伤神经元神经元亚群的特性 (ICV)细胞不透性荧光标记葡聚糖示踪剂在假手术和中枢液压冲击伤(CFPI)中的应用 动物。然后使用组织学和分子范式，我将评估膜破坏的神经元 细胞NeuN表达，以及未成熟神经元标志物的表达。顺便说一句，背后的机制 神经细胞膜的破坏是未知的，我们实验室以前的工作表明，当复合脑损伤时 随着大鼠颅内压的升高，神经细胞膜的破裂与颅内压直接相关。 立面。目的1b)评价二次颅内压升高对神经膜破裂的影响 亚群。我认为溶酶体组织蛋白酶B(Cath B)是一种潜在的膜破坏介质， 以前的发现表明，Cath B从溶酶体重新定位到胞浆，这已经通过 其他组织发起细胞损伤/死亡。我打算评估二次颅内压升高对 Neun膜破坏了Sham、CFPI动物和CFPI+升高的ICP动物的种群 通过显微镜和分子方法，上述相同的葡聚糖方案。同时，我会 研究Cath B在体内的作用，通过抑制假手术和损伤后的Cath B，然后使用活性测定 验证抑制和显微研究，以评估Cath B的重新定位。我预计在F99项目中 弥漫性颅脑损伤伴随着颅内压升高，稍后将会看到膜破裂人口的增加。然而，一个 代偿性神经元亚群减少，因为这些神经元将承受二次伤害。最后，它 预计脑损伤后膜损伤神经元中Cath-B从溶酶体重新定位到胞浆 并将因二次颅内压侮辱而加剧。

Diffuse traumatic brain injury (TBI) is associated with various pathologies that lead to long-term impairments, including post-traumatic headache (PTH), particularly migraine. There are worse outcomes of TBI when compounded with elevated intracranial pressure (ICP). The objective of the F99 work is to elucidate the mechanism(s) that may be attributed to TBI-induced pathologies and ICP-mediated diffuse pathologies. The objective of the K00 is to investigate cellular and molecular mechanisms of migraine to become an investigator of PTH in TBI. One pathology, neuronal membrane disruption, has been shown to be induced acutely post-TBI. However, my initial studies present that membrane disruption in neurons can last beyond the acute timeframe and last for weeks post-TBI. Furthermore, data indicate that there is a subpopulation of cortical neurons that do not express NeuN and are membrane disrupted. With other injuries, a NeuN negative (NeuN-) presentation has been indicative of a reversion to an immature neuronal phenotype. If injured neurons are reverting to an immature phenotype, then this could be a compensatory mechanism, so identifying these neurons that also are membrane disrupted may provide more insight into the molecular mechanism of membrane disruption. Aim 1a) is to investigate the identity of NeuN- subpopulation of membrane disrupted neurons using intracerebroventricular (ICV) cell impermeable fluorescently-tagged dextran tracer in sham and central fluid percussion injured (CFPI) animals. Then using histological and molecular paradigms, I will evaluate membrane disrupted neurons for cellular NeuN expression, and expression of immature neuronal markers. Incidentally, the mechanism behind neuronal membrane disruption is unknown, and previous work from our lab shows that when TBI is compounded with an elevation in ICP in rats, that neuronal membrane disruption is increased in direct relation to the ICP elevation. Aim 1b) is to evaluate the effects of secondary ICP elevation on the NeuN- membrane disrupted subpopulation. I propose that lysosomal Cathepsin B (Cath B) is a potential mediator of membrane disruption, as previous findings reveal that Cath B re-localizes from the lysosome to the cytosol, which has been shown by other groups to initiate cell damage/death. I intend to evaluate the effects of secondary ICP elevation on the NeuN- membrane disrupted population using sham, CFPI animals and CFPI+elevated ICP animals with the same dextran protocol aforementioned, via microscopic and molecular approaches. Simultaneously, I will investigate the role of Cath B in vivo by inhibiting Cath B following sham and injury then using activity assays to verify inhibition as well as microscopic studies to evaluate the re-localization of Cath B. I expect in the F99 project that diffuse TBI paired with elevated ICP will see increases in membrane disrupted population later. Yet, a reduction in the compensatory NeuN- subpopulation as these neurons will endure a secondary insult. Finally, it is expected that Cath-B is re-localizing from the lysosome to the cytosol after TBI in membrane disrupted neurons and will be exacerbated with secondary ICP insult.