Unilateral ischemic sensorimotor cortical damage induces contralesional synaptogenesis and enhances skilled reaching with the ipsilateral forelimb in adult male rats
Unilateral ischemic sensorimotor cortical damage induces contralesional synaptogenesis and enhances skilled reaching with the ipsilateral forelimb in adult male rats
复制标题
DOI：
10.1002/syn.20080
复制
发表时间：
2004-12-15
期刊：
影响因子：
2.3
通讯作者：
Jones, TA
中科院分区：
文献类型：
--
作者：
Luke, LM;Allred, RP;Jones, TA
感觉运动皮层（SMC）前肢代表区的单侧损伤导致对未受损（病变同侧）前肢的代偿依赖以及对侧运动皮层神经元结构和连接的重组。最近，发现单侧电解SMC病变的雄性大鼠与假手术对照组相比，具有增强的同侧前肢熟练达到性能。本研究进行，以确定这些行为的发现是否是可复制的使用缺血性病变，以及是否有一个链接之间的增强学习和突触在运动皮层第V层的训练肢体和病变，使用体视学方法进行评估，光镜和电镜。采用假手术或内皮素-1（ET-1）诱导的缺血性SMC损伤模型。然后，他们接受了20天的训练，用未受损的肢体完成熟练的伸展任务，或者接受控制程序。与以前的研究结果，使用电解损伤，单侧缺血性SMC病变的大鼠进行了显着更好地使用未受损的前肢比假手术。病变，但不是训练，显着增加运动皮层V层突触的总数，每个神经元以及穿孔和多突触扣（MSB）突触每个神经元的数量与假相比。因此，除了突触的净增加之外，达到能力的改善还伴随着突触亚型的增加，这些突触亚型先前与增强的突触功效有关。与以前的研究结果相反，未能诱导突触在层V达到单独的训练，可能与训练强度。(C)2004 Wiley-Liss，Inc.
Unilateral damage to the forelimb representation area of the sensorimotor cortex (SMC) results in a compensatory reliance on the unimpaired (ipsilateral to the lesion) forelimb as well as reorganization of neuronal structure and connectivity in the contralateral motor cortex. Recently, male rats with unilateral electrolytic SMC lesions were found to have enhanced skilled reaching performance with the ipsilesional forelimb compared with sham-operated controls. The present study was performed to determine whether these behavioral findings are replicable using an ischemic lesion and whether there is a link between the enhanced learning and synaptogenesis in motor cortical layer V opposite the trained limb and lesion, as assessed using stereological methods for light and electron microscopy. Rats were given a sham operation or an endothelin-1 (ET-1) induced ischemic SMC lesion. They were then trained for 20 days on a skilled reaching task with the unimpaired limb or received control procedures. As with previous findings using electrolytic lesions, rats with unilateral ischemic SMC lesions performed significantly better using the unimpaired forelimb than did sham-operates. Lesions, but not training, significantly increased the total number of motor cortical layer V synapses per neuron as well as the number of perforated and multisynaptic bouton (MSB) synapses per neuron compared with shams. Thus, in addition to a net increase in synapses, the improved reaching ability was coupled with an increase in synapse subtypes that have previously been linked to enhanced synaptic efficacy. The failure to induce synaptogenesis in layer V with reach training alone is in contrast to previous findings and may be related to training intensity. (C) 2004 Wiley-Liss, Inc.