Terminal arbors of axons projecting to the somatosensory cortex of the adult rat. II. The altered morphology of thalamocortical afferents following neonatal infraorbital nerve cut
Terminal arbors of axons projecting to the somatosensory cortex of the adult rat. II. The altered morphology of thalamocortical afferents following neonatal infraorbital nerve cut
复制标题
轴突的末端乔木突出到成年大鼠的体感皮层。
DOI：
10.1523/jneurosci.07-11-03544.1987
复制
发表时间：
1987
影响因子：
--
通讯作者：
H. Killackey
中科院分区：
文献类型：
--
作者：
KF Jensen;H. Killackey
在大鼠的新皮层内的晶须表示的组织是依赖于一个完整的外围在发展过程中。为了进一步研究如何在这个皮质地图的变化出现，我们检查了组织的丘脑皮质传入的胡须表示在成年动物中，三叉神经的眶下分支被切断的出生之日。丘脑皮质投射到触须代表的中断模式是明显的辣根过氧化物酶从丘脑的顺行运输的异常模式，以及在琥珀酸脱氢酶活性的异常模式。为了确定与这种破坏模式相关的单个丘脑皮质轴突的形态，通过将辣根过氧化物酶注射到体感皮质下方的白色物质中来“批量标记”终端乔木。终端乔木被确定其对应于特定的丘脑皮质传入的终扣的层状分布。这些终端乔木的内侧到外侧范围变化很大，从350到1500微米。此外，终末乔木支配同一局部区域的皮质似乎有不同程度的重叠。因此，新皮层触须代表的中断似乎涉及个别丘脑皮层传入神经的异常分支。这一发现支持了这样的假设，即躯体位置图的细粒度组织取决于单个丘脑皮质乔木的形态和组织，而这些形态和组织又取决于发育过程中的外围。
The organization of the whisker representation within the neocortex of the rat is dependent on an intact periphery during development. To further investigate how alterations in this cortical map arise we examined the organization of thalamocortical afferents to the whisker representation in adult animals in which the infraorbital branch of the trigeminal nerve was cut on the day of birth. The disrupted pattern of thalamocortical projections to the vibrissae representation was apparent in the abnormal pattern of the anterograde transport of horseradish peroxidase from the thalamus, as well as in the abnormal pattern of succinate dehydrogenase activity. To determine the morphology of individual thalamocortical axons associated with this disrupted pattern, terminal arbors were “bulk-labeled” by injections of horseradish peroxidase into the white matter beneath the somatosensory cortex. Terminal arbors were identified by their laminar distribution of boutons corresponding to the specific thalamocortical afferent. The medial to lateral extent of these terminal arbors varied dramatically, from 350 to 1500 microns. In addition, terminal arbors innervating the same local area of cortex appeared to have varying degrees of overlap. Thus, the disruption of the neocortical vibrissae representation appears to involve the abnormal arborization of individual thalamocortical afferents. This finding supports the hypothesis that the fine-grain organization of the somatotopic map is dependent on the morphology and organization of individual thalamocortical arbors, which, in turn, are dependent on the periphery during development.