Anatomical correlates of representational map reorganization induced by partial vibrissectomy in the barrel cortex of adult mice
Anatomical correlates of representational map reorganization induced by partial vibrissectomy in the barrel cortex of adult mice
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DOI：
10.1016/s0306-4522(98)00722-2
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发表时间：
1999-01-01
期刊：
影响因子：
3.3
通讯作者：
Juliano, SL
中科院分区：
文献类型：
--
作者：
Kossut, M;Juliano, SL
我们研究了皮层连通性变化的可能性，以伴随神秘性触须功能皮层表征的长期可塑性变化。切除C排须后，可引起年轻成年小鼠桶状皮质的可塑性。我们发现，2-脱氧葡萄糖脑作图导致了未受损伤触须皮层表征的渐进式扩张。在切除2个月后，待留行触须皮质图宽度加倍后，注射荧光右旋糖酐活的桶状皮质切片。注射集中在备用、剥夺和控制振动柱上。注射标记了三个皮质内投射系统：(i)从一个振动柱到邻近柱的局部连接；（ii）在桶的隔层和壁中延伸并跨越几个桶的远程投影；在第iii层和第IV层的柱中心进行少量注射后，分析了局部的短程投射系统。我们发现，与注射到剥夺或对照的桶中相比，注射到空闲桶中的标记轴突在所有层中延伸的距离都要大得多（除了第V层），并且标记细胞体的位置也要远得多。此外，注射到空桶中标记的总轴突密度比剥夺或对照桶高70%。成人体感觉皮层地形图的改变可能在功能性去神经支配后立即发生，但也可能随着时间的推移而增加，就像我们的实验情况一样。我们的研究结果表明，持续的、长期的塑性变化可以重塑桶状皮质的连通性。(c) 1999年ibro。Elsevier Science Ltd.出版。
We examined the potential for changes in cortical connectivity to accompany long-term plastic changes in functional cortical representations of mystacial vibrissae. Plasticity in the barrel cortex of young adult mice was evoked by vibrissectomy that spared row C of whiskers. We found that 2-deoxyglucose brain mapping causes a progressive expansion of cortical representation bf the spared vibrissae. Two months after vibrissectomy, when the width of the cortical map of the spared row of vibrissae doubled, living cortical slices of the barrel cortex were injected with fluorescent dextrans. The injections were centered on spared, deprived and control vibrissal columns. The injections labeled three intracortical projection systems: (i) local connections from one vibrissal column to neighboring columns; (ii) long-range projections running in the septa and walls of the barrels and spanning several barrels; and (iii) very-long-range fibers running horizontally in the lower part of layer V. The local, short-range projection system was analysed following small injections into the centers of columns in layers III and IV. We found that injections into spared barrels labeled axons extending for significantly greater distances in all layers (except layer V), and labeled cell bodies situated significantly further, than after injections into deprived or control barrels. Also, the total axonal density labeled by injections into the spared barrel was higher by 70% than for the deprived or control barrels. Alterations of topographical maps in adult somatosensory cortex may occur immediately after functional denervation, but may also increase with time, as in the case of our experimental situation.Our results indicate that persistent, long-term plastic change can remodel connectivity in the barrel cortex. (C) 1999 IBRO. Published by Elsevier Science Ltd.