The effects of transplantation and regeneration of sensory neurons on a somatotopic map in the cricket central nervous system.
The effects of transplantation and regeneration of sensory neurons on a somatotopic map in the cricket central nervous system.
复制标题
感觉神经元移植和再生对蟋蟀中枢神经系统体位图的影响。
DOI：
10.1016/0012-1606(81)90168-8
复制
发表时间：
1981
影响因子：
2.7
通讯作者：
Walthall,WW
中科院分区：
文献类型：
--
作者：
Murphey,RK;Johnson,SE;Walthall,WW
在切断颈神经或切除宫颈并重新植入后，观察蟋蟀颈部传入投射的恢复情况。在任一动作后，感觉神经元在大约1个月内在中枢神经系统(CNS)再生树枝。为了评估通往中枢神经系统的通路在控制终末分支生长中的作用，我们将左侧宫颈移植到宿主的右侧。手术不匹配宿主组织和移植物组织的内侧轴线。在三分之一被检查的神经元中，再生神经元的轴突轨迹发生了变化。这些病例的终末分支是不寻常的；例如，一个神经元在异常区域和其正常区域分支。在极少数情况下，这种神经元只分布在中枢神经系统的错误区域。因此，轴突通路似乎可以对感觉神经元的中枢结构产生影响。然而，在手术后的大多数情况下，神经元即使通过迂回的路线也能够到达它们适当的靶区。该图的近端坐标与感觉神经元年龄同构，因为大多数远端受体是在胚胎后发育的早期产生的，而新的受体在每一次蜕皮时都会在近端添加。我们通过两个实验验证了分化的顺序对产生传入投射至关重要的可能性。首先，包括锁骨阵列远端成员的远端颈椎被截断。标本再生了一个完整的远端宫颈，包括远端锁骨受体。当新生成的远端神经元被染色时，末端茎与它们替换的被截断的神经元相同。在这种情况下，年龄和到达顺序都与正常相反，但地形投影模式没有改变。其次，我们将年轻的宫颈移植到较老的标本上，然后检查移植的感觉神经元再生的茎。未成熟的神经元在成年神经系统中与成熟的同系物完全一样。因此，感觉神经元的年龄似乎不是终末树枝形成过程中的控制变量。这些结果的意义在发展有序神经元连接的两个模型的背景下进行了讨论。
The restoration of the cercal afferent projection of crickets was examined after severing the cercal nerve or amputating the cercus and reimplanting it. After either maneuver the sensory neurons regenerated arborizations in the central nervous system (CNS) within about 1 month. In order to assess the role of the pathway taken to the CNS in controlling the growth of the terminal arborization, we transplantated left cerci to the right side of the host. The operation mismatched the mediolateral axes of host and graft tissues. In one-third of the neurons examined, the axon trajectories of the regenerated neurons were altered. The terminal arborizations in these cases were unusual; for example, one neuron arborized in an abnormal area as well as in its normal area. In rare instances this neuron arborized only in incorrect areas of the CNS. Thus, it appears that axon pathway can have an effect on the central structure of sensory neurons. However, in most cases after the surgery, the neurons were able to reach their proper target areas even by circuitous routes. The proximodistal coordinate of the map is isomorphic with sensory neuron age, because the most distal receptors are produced early in postembryonic development and new ones are added proximally at each molt. We tested the possibility that the order of differentiation was critical for generating the afferent projection with two experiments. First, the distal cercus including the distal members of the clavate array was amputated. The specimen regenerated an entire distal cercus including distal clavate receptors. When newly generated, distal neurons were stained, the terminal arbors were identical to the amputated neurons they replaced. In this case, both age and order of arrival were reversed from normal yet the topographic projection pattern was not altered. Second, we transplanted young cerci onto older specimens and then examined the regenerated arbors of the transplanted sensory neuron. The immature neuron arborized in the adult nervous system exactly as the mature homolog. Thus the age of a sensory neuron did not appear to be a controlling variable in the elaboration of a terminal arborization. The significance of these results is discussed in the context of two models for development of orderly neuronal connections.