Dose-dependent neuronal injury after traumatic brain injury
Dose-dependent neuronal injury after traumatic brain injury
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DOI：
10.1016/j.brainres.2005.02.054
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发表时间：
2005-05-24
期刊：
影响因子：
2.9
通讯作者：
Prough, DS
中科院分区：
文献类型：
--
作者：
Hellmich, HL;Capra, B;Prough, DS
Fluoro-Jade（FJ）染色可靠地识别多种脑损伤机制后的退化神经元。我们修改了FJ染色方案，以快速染色冷冻海马大鼠脑切片，并允许系统计数染色，损伤神经元在4和24小时后，轻度，中度或重度液压冲击创伤性脑损伤（TBI）。在相邻切片中，使用激光捕获显微切割来收集未损伤的（FJ阴性）CA 3海马神经元，以评估损伤严重程度对所选基因的mRNA水平的影响。将大鼠麻醉、插管、机械通气并随机分为假手术组、轻度（1.2 atm）、中度（2.0 atm）或重度（2.3 atm）TBI组。TBI后4或24小时，从每只大鼠的海马收集10个冷冻切片（10 μ m厚，每15个切片），用FJ染色并用甲酚紫复染。在海马CA 1、CA 3亚区和齿状回/齿状门区计数Fluoro-Jade阳性神经元。在4和24小时后TBI，FJ阳性神经元在所有海马区域的数量增加剂量依赖性在轻度和中度损伤的大鼠，但没有显着更多的严重损伤后。尽管方差分析表明，在所有损伤水平下，未损伤的CA 3神经元中热休克蛋白70、bcl-2、caspase 3、caspase 9和白细胞介素-1 β的mRNA表达水平没有总体差异，但事后分析表明，TBI诱导神经保护基因表达的增加，从而抵消了伴随的有害基因表达的增加。(c)2005 Elsevier B. V.保留所有权利。
The Fluoro-Jade (FJ) stain reliably identifies degenerating neurons after multiple mechanisms of brain injury. We modified the FJ staining protocol to quickly stain frozen hippocampal rat brain sections and to permit systematic counts of stained, injured neurons at 4 and 24 h after mild, moderate or severe fluid percussion traumatic brain injury (TBI). In adjacent sections, laser capture microdissection was used to collect uninjured (FJ negative) CA3 hippocampal neurons to assess the effect of injury severity on mRNA levels of selected genes. Rats were anesthetized, intubated, mechanically ventilated and randomized to sham, mild (1.2 atm), moderate (2.0 atm) or severe (2.3 atm) TBI. Four or 24 h post-TBI, ten frozen sections (10 mu m thick, every 15th section) were collected from the hippocampus of each rat, stained with FJ and counterstained with cresyl violet. Fluoro-Jade-positive neurons were counted in hippocampal subfields CA1, CA3 and the dentate gyrus/ dentate hilus. At both 4 and 24 h post-TBI, numbers of FJ-positive neurons in all hippocampal regions increased dose-dependently in mildly and moderately injured rats but were not significantly more numerous after severe injury. Although analysis of variance demonstrated no overall difference in expression of mRNA levels for heat shock protein 70, bcl-2, caspase 3, caspase 9 and interleukin-1 beta in uninjured CA3 neurons at all injury levels, post hoc analysis suggested that TBI induces increases in neuroprotective gene expression that offset concomitant increases in deleterious gene expression. (c) 2005 Elsevier B.V. All rights reserved.