TRACT TRACING IN FIXED POSTMORTEM HUMAN BRAIN

我们建议应用快速di-I道跟踪方法，通常 需要3-4个月才能穿透1厘米，非常迅速（1-2小时） 人类大脑解剖材料后，立即大脑已被 移除，延迟固定，直到大约24小时后。 我们的初步 对延迟固定的人脑样本的研究显示， 仅在24小时内就能达到比 在先前发表的研究中使用固定材料实现的距离 以及三到四个月的穿透时间。 具体目标1： 以初级视皮层为模型， 系统 特定目标2测试最大投影距离 可通过使用运动皮层模型的方法获得。 具体目标 三是优化方法。 尽管有局限性，延迟- 固定DI-I方法应该为定义人类 脑细胞结构，可能有助于研究特定的 神经系统疾病的脆弱性。

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.