Oron Amir, Oron Uri, Chen Jieli, Eilam Anda, Zhang Chunling, Sadeh Menachem, Lampl Yair, Streeter Jackson, DeTaboada Luis, Chopp Michael
Department of Orthopedics, Assaf Harofeh Medical Center, Zerifin 70300, Israel.
Stroke. 2006 Oct;37(10):2620-4. doi: 10.1161/01.STR.0000242775.14642.b8. Epub 2006 Aug 31.
Low-level laser therapy (LLLT) modulates various biological processes. In the present study, we assessed the hypothesis that LLLT after induction of stroke may have a beneficial effect on ischemic brain tissue.
Two sets of experiments were performed. Stroke was induced in rats by (1) permanent occlusion of the middle cerebral artery through a craniotomy or (2) insertion of a filament. After induction of stroke, a battery of neurological and functional tests (neurological score, adhesive removal) was performed. Four and 24 hours poststroke, a Ga-As diode laser was used transcranially to illuminate the hemisphere contralateral to the stroke at a power density of 7.5 mW/cm2.
In both models of stroke, LLLT significantly reduced neurological deficits when applied 24 hours poststroke. Application of the laser at 4 hours poststroke did not affect the neurological outcome of the stroke-induced rats as compared with controls. There was no statistically significant difference in the stroke lesion area between control and laser-irradiated rats. The number of newly formed neuronal cells, assessed by double immunoreactivity to bromodeoxyuridine and tubulin isotype III as well as migrating cells (doublecortin immunoactivity), was significantly elevated in the subventricular zone of the hemisphere ipsilateral to the induction of stroke when treated by LLLT.
Our data suggest that a noninvasive intervention of LLLT issued 24 hours after acute stroke may provide a significant functional benefit with an underlying mechanism possibly being induction of neurogenesis.
低强度激光疗法（LLLT）可调节多种生物学过程。在本研究中，我们评估了以下假设：中风诱导后进行低强度激光疗法可能对缺血性脑组织产生有益影响。
进行了两组实验。通过以下两种方式在大鼠中诱导中风：（1）通过开颅手术永久性闭塞大脑中动脉；（2）插入一根细丝。中风诱导后，进行了一系列神经学和功能测试（神经学评分、去除黏附物）。中风后4小时和24小时，使用砷化镓二极管激光经颅照射中风对侧半球，功率密度为7.5 mW/cm²。
在两种中风模型中，中风后24小时应用低强度激光疗法均显著降低了神经功能缺损。与对照组相比，中风后4小时应用激光对中风诱导大鼠的神经学结局没有影响。对照组和激光照射组大鼠的中风损伤面积没有统计学显著差异。通过对溴脱氧尿苷和微管蛋白同种型III进行双重免疫反应以及对迁移细胞（双皮质素免疫活性）进行评估，发现中风诱导同侧半球脑室下区新形成的神经元细胞数量在接受低强度激光疗法治疗时显著增加。
我们的数据表明，急性中风后24小时进行的低强度激光疗法非侵入性干预可能提供显著的功能益处，其潜在机制可能是诱导神经发生。
