Zhang Shengxiang, Boyd Jamie, Delaney Kerry, Murphy Timothy H
Kinsmen Laboratory, Department of Psychiatry, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z3.
J Neurosci. 2005 Jun 1;25(22):5333-8. doi: 10.1523/JNEUROSCI.1085-05.2005.
Current therapeutic windows for effective application of thrombolytic agents are within 3-6 h of stroke. Although treatment can improve outcome, it is unclear what happens to synaptic fine structure during this critical period in vivo. The relationship between microcirculation and dendritic spine structure was determined in mouse somatosensory neurons during stroke. Spines were, on average, 13 mum from a capillary and were supplied by approximately 100 red blood cells per second. Moderate ischemia (approximately 50% supply) did not significantly affect spines within 5 h; however, severe ischemia (<10% supply) caused a rapid loss of spine and dendrite structure within as little as 10 min. Surprisingly, if reperfusion occurred within 20-60 min, dendrite and spine structure was mostly restored. These data suggest that the basic dendritic wiring diagram remains mostly intact during moderate ischemia and that affected synapses could potentially contribute to functional recovery. With severe ischemia, markedly deformed dendritic structure can partially recover if reperfusion occurs early.
目前溶栓药物有效应用的治疗窗是在中风后的3 - 6小时内。尽管治疗可以改善预后，但在此关键的体内时期突触精细结构会发生什么尚不清楚。在中风期间，研究了小鼠体感神经元中微循环与树突棘结构之间的关系。树突棘平均距离毛细血管13微米，每秒约有100个红细胞供应。中度缺血（约50%的供血）在5小时内不会对树突棘产生显著影响；然而，严重缺血（供血<10%）在短短10分钟内就会导致树突棘和树突结构迅速丧失。令人惊讶的是，如果在20 - 60分钟内发生再灌注，树突和树突棘结构大多会恢复。这些数据表明，在中度缺血期间基本的树突布线图大多保持完整，并且受影响的突触可能有助于功能恢复。在严重缺血时，如果早期发生再灌注，明显变形的树突结构可以部分恢复。
