Briones Teresita L, Suh Eugene, Jozsa Lauren, Rogozinska Magdalena, Woods Julie, Wadowska Maggie
Department of Medical-Surgical Nursing, University of Illinois at Chicago, 845 S. Damen Avenue, Room 707, M/C 802, Chicago, IL 60612, USA.
Brain Res. 2005 Feb 1;1033(1):51-7. doi: 10.1016/j.brainres.2004.11.017.
Damage to the adult brain can result in adaptive plasticity in regions adjacent to the site of the principal insult and that the plastic changes may be modulated by post-injury rehabilitation training. In this study, we examined the effects of rehabilitation training on synaptic morphology in the dentate gyrus following transient global cerebral ischemia and the metabolic correlates of the ultrastructural changes. Forty adult male Wistar rats were included in the study and assigned to either ischemia or sham group. Following ischemic or sham surgery, rats were randomized to either complex environment housing (EC), exercise (EX), or social condition (SC, paired housing) group. Electron microscopy and unbiased stereological methods were used to evaluate synaptic plasticity and the number and size of mitochondria in synaptic axon terminals. Increased number of granule neurons was seen in all ischemic groups and in the sham EC rats. Changes in the number of synapses per neuron in the outer and inner molecular layers of the dentate gyrus parallel those seen in granule neurons. Similarly, ischemia and behavioral experience in EC independently increased the number of synaptic mitochondria in presynaptic terminals in both the outer and inner molecular layers; however, no significant changes were seen in mitochondrial size. These data suggest a link between behavioral training and synaptic plasticity in the region adjacent to the injury and that the likely metabolic correlate of this synaptic plasticity is increased number of mitochondria at synaptic axon terminals.
成人大脑受损可导致主要损伤部位附近区域出现适应性可塑性变化，且这些可塑性变化可能受到损伤后康复训练的调节。在本研究中，我们检测了康复训练对短暂性全脑缺血后齿状回突触形态的影响以及超微结构变化的代谢相关性。该研究纳入了40只成年雄性Wistar大鼠，并将其分为缺血组或假手术组。在进行缺血或假手术后，将大鼠随机分为复杂环境饲养（EC）组、运动（EX）组或社交条件（SC，配对饲养）组。采用电子显微镜和无偏立体学方法评估突触可塑性以及突触轴突终末中线粒体的数量和大小。在所有缺血组以及假手术EC大鼠中均可见颗粒神经元数量增加。齿状回外分子层和内分子层中每个神经元突触数量的变化与颗粒神经元中的变化相似。同样，缺血和在EC中的行为经历独立增加了外分子层和内分子层突触前终末中突触线粒体的数量；然而，线粒体大小未见显著变化。这些数据表明行为训练与损伤附近区域的突触可塑性之间存在联系，且这种突触可塑性可能的代谢相关性是突触轴突终末线粒体数量增加。
