Displacement of Sensory Maps and Disorganization of Motor Cortex After Targeted Stroke in Mice
Displacement of Sensory Maps and Disorganization of Motor Cortex After Targeted Stroke in Mice
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DOI：
10.1161/strokeaha.113.001272
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发表时间：
2013-08-01
期刊：
影响因子：
8.3
通讯作者：
Murphy, Timothy H.
中科院分区：
文献类型：
--
作者：
Harrison, Thomas C.;Silasi, Gergely;Murphy, Timothy H.
背景和目的 据推测，中风的恢复涉及幸存皮质区域的重组。为了研究中风前后多个时间点感觉运动皮层的功能组织，我们对第 5 层皮层神经元中表达光敏通道视紫红质 2 的转基因小鼠进行了纵向光运动映射。方法将光刺激脉冲瞄准一系列皮层点，同时使用无创运动传感器记录诱发的前肢运动活动。内在光学信号成像产生前肢体感皮层的图。在针对前肢运动或感觉皮层的小（0.2 mm(3)）光血栓性梗死之前和之后数周内重复生成由此产生的运动和感觉图。结果针对前肢感觉或运动区域的梗塞导致梗塞区域的运动输出减少以及感觉和运动图的空间位移。感觉皮层的敲击导致感觉图移动到运动皮层，运动皮层采用了更分散的结构。运动皮层中风引起梗死周围运动输出的代偿性增加，但不影响感觉图的位置或兴奋性。结论运动皮层中风后，梗死区域运动输出的减少被梗塞周围兴奋性所抵消。感觉中风导致运动皮层形成新的感觉图，尽管变得更加分散，但仍保持其中心位置。这些数据表明，幸存的皮质区域能够承担中风受损区域的功能，尽管这可能是以地图结构改变为代价的。
Background and Purpose Recovery from stroke is hypothesized to involve the reorganization of surviving cortical areas. To study the functional organization of sensorimotor cortex at multiple time points before and after stroke, we performed longitudinal light-based motor mapping of transgenic mice expressing light-sensitive channelrhodopsin-2 in layer 5 cortical neurons.Methods Pulses of light stimulation were targeted to an array of cortical points, whereas evoked forelimb motor activity was recorded using noninvasive motion sensors. Intrinsic optical signal imaging produced maps of the forelimb somatosensory cortex. The resulting motor and sensory maps were repeatedly generated for weeks before and after small (0.2 mm(3)) photothrombotic infarcts were targeted to forelimb motor or sensory cortex.Results Infarcts targeted to forelimb sensory or motor areas caused decreased motor output in the infarct area and spatial displacement of sensory and motor maps. Strokes in sensory cortex caused the sensory map to move into motor cortex, which adopted a more diffuse structure. Stroke in motor cortex caused a compensatory increase in peri-infarct motor output, but did not affect the position or excitability of sensory maps.Conclusions After stroke in motor cortex, decreased motor output from the infarcted area was offset by peri-infarct excitability. Sensory stroke caused a new sensory map to form in motor cortex, which maintained its center position, despite becoming more diffuse. These data suggest that surviving regions of cortex are able to assume functions from stroke-damaged areas, although this may come at the cost of alterations in map structure.