Lesage Frédéric, Brieu Nicolas, Dubeau Simon, Beaumont Eric
Département de génie électrique, Ecole Polytechnique de Montréal, Montréal, Québec, Canada.
Neurosci Lett. 2009 Apr 17;454(1):105-9. doi: 10.1016/j.neulet.2009.02.060. Epub 2009 Mar 3.
Neuronal and vascular reorganization after spinal cord injury (SCI) is scarcely known although its characterization has major implications in understanding the functioning of the altered spinal cord. Several electrophysiological and anatomical lines of evidence support plasticity caudal to the lesion site, but do not provide sufficient clues about neuronal and vascular reorganization after SCI. The aim of the present study was to compare neuronal activation in the lumbar spinal cord between uninjured and SCI rats with novel optical imaging technology. The results showed significant haemodynamic response differences after sciatic nerve stimulation in uninjured controls, in comparison to SCI rats. Both timing and shape of the response were modified. In uninjured rats, blood flow presented an initial dip but was rapidly drained from the activation site through the venous system. In comparison, the blood transfer rate in SCI rats was much slower. Damaged blood vessels at the lesion site after thoracic SCI impacted the vascular response upon neuronal activation in the lumbar spinal cord. This observation is important in the study of spinal cord function after SCI by imaging techniques based on haemodynamics (blood oxygenation level-dependent using functional magnetic resonance imaging (BOLD fMRI) and optical imaging). In conclusion, our results indicate that new avenues quantifying the influence of vascular plumbing will have to be developed to explore the efficacy of rehabilitation and pharmacological therapies by haemodynamic imaging.
脊髓损伤（SCI）后神经元和血管的重组情况鲜为人知，尽管其特征对于理解受损脊髓的功能具有重要意义。几条电生理和解剖学证据支持损伤部位尾侧的可塑性，但并未提供足够线索来了解脊髓损伤后的神经元和血管重组。本研究的目的是使用新型光学成像技术比较未受伤大鼠和脊髓损伤大鼠腰段脊髓中的神经元激活情况。结果显示，与脊髓损伤大鼠相比，未受伤对照组在坐骨神经刺激后血流动力学反应存在显著差异。反应的时间和形状均发生了改变。在未受伤的大鼠中，血流最初出现下降，但随后通过静脉系统迅速从激活部位排出。相比之下，脊髓损伤大鼠的血液转移速度要慢得多。胸段脊髓损伤后损伤部位的血管受损影响了腰段脊髓神经元激活时的血管反应。这一观察结果对于通过基于血流动力学的成像技术（使用功能磁共振成像（BOLD fMRI）和光学成像的血氧水平依赖）研究脊髓损伤后的脊髓功能具有重要意义。总之，我们的结果表明，必须开辟新途径来量化血管通路的影响，以便通过血流动力学成像探索康复和药物治疗的效果。
