Evidence that descending cortical axons are essential for thalamocortical axons to cross the pallial-subpallial boundary in the embryonic forebrain.
Evidence that descending cortical axons are essential for thalamocortical axons to cross the pallial-subpallial boundary in the embryonic forebrain.
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DOI：
10.1371/journal.pone.0033105
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发表时间：
2012
期刊：
影响因子：
3.7
通讯作者：
Price DJ
中科院分区：
文献类型：
--
作者：
Chen Y;Magnani D;Theil T;Pratt T;Price DJ
发育中的丘脑皮质轴突穿过下腭到达位于腭中的皮质。我们测试了这一假设，即下行离皮质轴突是重要的指导丘脑皮层轴突跨越苍白球-苍白球下边界，使用条件性诱变，以评估阻断离皮质轴突的发展，而不破坏丘脑，苍白球下或苍白球-苍白球下边界的影响。我们发现，丘脑轴突仍然穿越的腭下的地形秩序，但没有跨越苍白球-苍白球下的边界。共培养实验表明，丘脑轴突无法跨越边界并不能用突变皮质对丘脑轴突产生远程化学排斥作用来解释。相反，条件突变体的皮质保留了其丘脑轴突生长促进活性，并继续表达Nrg-1，这是负责这种刺激作用。当突变体皮质被替换为控制皮质，离皮质传出神经恢复和条件突变体与他们的丘脑轴突，并越过苍白球-苍白球下边界。我们的研究提供了迄今为止最令人信服的证据，皮质传出需要引导丘脑皮层轴突穿过苍白球-苍白球下边界，否则丘脑轴突是敌对的。这些结果支持了这一假设，丘脑轴突生长从下腭皮质的皮质传出神经的指导下，从可扩散的皮质生长促进因子的刺激。
Developing thalamocortical axons traverse the subpallium to reach the cortex located in the pallium. We tested the hypothesis that descending corticofugal axons are important for guiding thalamocortical axons across the pallial-subpallial boundary, using conditional mutagenesis to assess the effects of blocking corticofugal axonal development without disrupting thalamus, subpallium or the pallial-subpallial boundary. We found that thalamic axons still traversed the subpallium in topographic order but did not cross the pallial-subpallial boundary. Co-culture experiments indicated that the inability of thalamic axons to cross the boundary was not explained by mutant cortex developing a long-range chemorepulsive action on thalamic axons. On the contrary, cortex from conditional mutants retained its thalamic axonal growth-promoting activity and continued to express Nrg-1, which is responsible for this stimulatory effect. When mutant cortex was replaced with control cortex, corticofugal efferents were restored and thalamic axons from conditional mutants associated with them and crossed the pallial-subpallial boundary. Our study provides the most compelling evidence to date that cortical efferents are required to guide thalamocortical axons across the pallial-subpallial boundary, which is otherwise hostile to thalamic axons. These results support the hypothesis that thalamic axons grow from subpallium to cortex guided by cortical efferents, with stimulation from diffusible cortical growth-promoting factors.
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影响因子：
2.7
作者：
Liu, Y;Ford, BD;Fischbach, GD
通讯作者：
Fischbach, GD
影响因子：
64.8
作者：
Iwasato, T;Datwani, A;Itohara, S
通讯作者：
Itohara, S
DOI：
10.1073/pnas.96.9.5037
发表时间：
1999-04-27
影响因子：
11.1
作者：
Mao, XH;Fujiwara, Y;Orkin, SH
通讯作者：
Orkin, SH
影响因子：
16.2
作者：
Flames, N;Long, JE;Marín, O
通讯作者：
Marín, O
DOI：
10.1093/cercor/bhp035
发表时间：
2009-07
期刊：
Cerebral cortex (New York, N.Y. : 1991)
影响因子：
--
作者：
Braisted JE;Ringstedt T;O'Leary DD
通讯作者：
O'Leary DD