Xerri C, Zennou-Azougui Y, Coq J-O
National Center of Scientific Research (CNRS), University of Provence Faculty of Sciences, St. Jérôme, Marseille Cedex, France.
ILAR J. 2003;44(2):110-24. doi: 10.1093/ilar.44.2.110.
Acute and chronic postlesion reorganization of the cortical maps was examined in adult rats using electrophysiological mapping of the forepaw area in the primary somatosensory cortex. Recordings were made before and after (first 12 hr and 3 wk) induction of a focal thermal-ischemic lesion to a restricted part of the forepaw area. The influence of an anti-ischemic substance (piracetam) and housing in an enriched environment (EE) or impoverished environment (IE) on the organization of the spared regions of the cortical maps adjacent to the lesion was investigated. The results revealed (1) a gradual expansion of the injured zone and a cellular loss that were smaller in the piracetam-treated (PT) rats than in the placebo (PL) rats; (2) a better preservation of the somatotopic organization and the neuronal responsiveness in the maps of the PT rats during the first 12 hr after the lesion; (3) a gradual compression and fragmentation of the remaining forepaw map over the first 3 postlesion wk. These changes were found in all PL rats, with the most detrimental effects in the animals exposed to an IE. In the PT-EE animals, a contrasting substantial preservation of the map was observed. (4) Cortical responsiveness was diminished in the PL rats, whatever the environment, and in the PT-IE rats; but it was not significantly affected in the PT-EE animals. The findings demonstrate the protective function of acute piracetam treatment on electrophysiological properties of cortical neurons within the peri-infarct tissue and highlight the neuroprotective effects of an environmental therapy combined with the piracetam treatment during the weeks after ischemic damage.
利用对成年大鼠初级体感皮层前爪区域进行电生理图谱分析，研究了损伤后急性和慢性皮层图谱的重组情况。在对前爪区域的一个受限部分诱导局灶性热缺血损伤之前和之后（最初12小时和3周）进行记录。研究了一种抗缺血物质（吡拉西坦）以及饲养于丰富环境（EE）或贫乏环境（IE）对损伤邻近皮层图谱 spared 区域组织的影响。结果显示：（1）损伤区域逐渐扩大，细胞损失在吡拉西坦治疗组（PT）大鼠中比安慰剂（PL）大鼠中更小；（2）在损伤后的最初12小时内，PT大鼠图谱中的躯体定位组织和神经元反应性保存得更好；（3）在损伤后的前3周，剩余前爪图谱逐渐压缩和碎片化。所有PL大鼠都出现了这些变化，在暴露于IE环境的动物中影响最为严重。在PT - EE动物中，观察到图谱有明显的保存情况。（4）无论环境如何，PL大鼠以及PT - IE大鼠的皮层反应性均降低；但PT - EE动物的皮层反应性未受到显著影响。这些发现证明了急性吡拉西坦治疗对梗死周围组织内皮层神经元电生理特性的保护作用，并突出了缺血损伤后数周内环境疗法与吡拉西坦治疗相结合的神经保护作用。
