TRACT TRACING IN FIXED POSTMORTEM HUMAN BRAIN

我们建议应用快速di-i轨迹跟踪方法，该方法通常 需要3-4个月才能穿透1厘米，速度极快(1-2小时) 人脑尸检材料后立即对大脑进行 移走，将固定推迟到大约24小时后。我们的预赛 对延迟固定人脑样本的研究表明，延迟固定的人脑样本 更长的示踪剂穿透距离，只需24小时 在以前发表的使用固定材料的研究中实现的距离 以及三到四个月的渗透时间。具体目标1旨在 以初级视皮层为模型，确认并扩展这些数据 系统。《特定目标2》测试最大投影距离 可通过使用运动皮质模型的方法获得。特定目标 3寻求优化方法。尽管有限制，但延迟的- 固定di-i方法应该为定义人类提供一个有用的工具 脑细胞结构，并可能有助于研究特定的 神经系统疾病中通路的脆弱性。

We propose to apply the fast di-I tract-tracing method, which normally requires 3-4 months to penetrate 1 cm, to extremely rapid (1-2 hours) human brain autopsy material immediately after the brain has been removed, delaying fixation until some 24 hours later. Our preliminary studies with delayed-fixation human brain samples show 5- to 10-fold more lengthy tracer penetration distances in only 24 hours than the distances achieved in previously published studies with fixed material and three to four months penetration time. Specific aim 1 seeks to confirm and extend these data using primary visual cortex as a model system. Specific Aim 2 tests the maximum projection distance obtainable with the method using a motor cortex model. Specific Aim 3 seeks to optimize the method. Despite limitations, the delayed- fixation di-I approach should provide a useful tool for defining human brain cytoarchitecture and may be helpful in studies of specific vulnerabilities of pathways in neurologic disease.