Steward O
Brain Res. 1980 Feb 10;183(2):277-89. doi: 10.1016/0006-8993(80)90464-3.
Unilateral destruction of the entorhinal area in the rat results in the proliferation of a pathway from the surviving contralateral entorhinal area to the fascia dentata denervated by the lesions (the crossed temporodentate pathway). The present study analyzes the point of entry of these reinnervating fibers into the fascia dentata, and their trajectory within the reinnervated zones utilizing orthograde transport of tritiated proline or horseradish peroxidase (HRP). Following injections of tritiated proline or HRP into the surviving entorhinal area in animals with long standing unilateral entorhinal lesions labeled axons could be visualized entering the contralateral fascia dentata via two routes. Labeled fibers could be traced from the dorsal hippocampal commissure (the dorsal psalterium) into the rostral tip of the fascia dentata (the fasciola cinerea) and from the terminal field of the crossed temporo-ammonic tract in regio superior into adjacent portions of the stratum moleculare of the fascia dentata. Within the stratum moleculare, most of the labeled axons had predominantly a caudal and lateral orientation. Exceptions to this predominant trajectory were found in the case of some of the axons which entered the ventral blade of the rostral fascia dentata, and coursed laterally from their point of entry. Comparisons of the trajectory of the crossed temporodentate projections with that of the normal ipsilateral pathway indicated that while the predominant trajectory of the fibers was roughly comparable, the polarity of the projections was in part opposite. Specifically, the normal ipsilateral pathway travels in a caudorostral direction, while the majority of fibers of the crossed temporodentate pathway apparently project rostrocaudally. The significance of this difference in the pattern of innervation is discussed with respect to the normal functioning of the temporodentate circuitry.
大鼠内嗅区单侧损毁会导致一条通路的增生，该通路从存活的对侧内嗅区通向因损伤而失神经支配的齿状回（交叉颞齿状通路）。本研究利用氚化脯氨酸或辣根过氧化物酶（HRP）的顺行运输，分析这些重新支配的纤维进入齿状回的切入点及其在重新支配区域内的轨迹。在长期单侧内嗅区损伤的动物中，将氚化脯氨酸或HRP注入存活的内嗅区后，可观察到标记的轴突通过两条途径进入对侧齿状回。标记的纤维可从背海马连合（背侧琴带）追踪到齿状回的吻端（灰带），并从颞-氨束交叉在上级区域的终末场追踪到齿状回分子层的相邻部分。在分子层内，大多数标记的轴突主要呈尾侧和外侧方向。在一些进入吻侧齿状回腹侧叶片的轴突中，发现了这种主要轨迹的例外情况，它们从进入点向外侧走行。将交叉颞齿状投射的轨迹与正常同侧通路的轨迹进行比较表明，虽然纤维的主要轨迹大致相似，但投射的极性部分相反。具体而言，正常同侧通路沿尾-吻方向走行，而交叉颞齿状通路的大多数纤维显然向吻-尾方向投射。本文就颞齿状回路的正常功能讨论了这种神经支配模式差异的意义。
