Katz L C, Driscoll M, Zimmermann K, Wiesel T N
Department of Neurobiology, Duke University Medical Center, Durham, NC 27710.
Brain Res Brain Res Rev. 1992 May-Aug;17(2):171-81. doi: 10.1016/0165-0173(92)90013-c.
The FESN-sponsored follow-up meeting on neural development highlighted progress toward understanding several central issues in developmental neurobiology with particular emphasis on investigation into the mechanisms of cell fate determination. In systems as diverse as the HSN neurons of C. elegans, the photoreceptor cells of the Drosophila eye, the wide range of cell types within the vertebrate retina and the neurons of the cerebral cortex, hindbrain and spinal cord, the importance of environment in the determination and maintenance of cell fate was clearly established. Advances in cell marking techniques, including fluorescent dye and retroviral tagging, have enabled the fates of cells in normal and heterotypic environments to be followed and have demonstrated the initial plasticity of the progenitor cell population in many systems. The recent establishment of in vitro systems for studying neural development should further define the precise nature and identity of the environmental signals that act to establish and maintain cell fate. Of course, establishment of cell identity is only the initial phase in the formation of the mature nervous system. Once the fate of individual cells is determined, migration of cells to appropriate locations, extension of axons to appropriate targets and refinement of neuronal circuitry must occur. Both the definition of genes that influence these processes in nematodes and recent advances in imaging techniques that provide a means of observing these later, dynamic processes in 'living' brain slices promise to significantly advance understanding of the complexities of development of functional nervous systems.
由FESN赞助的神经发育后续会议强调了在理解发育神经生物学几个核心问题方面取得的进展，尤其着重于对细胞命运决定机制的研究。在诸如秀丽隐杆线虫的HSN神经元、果蝇眼睛的光感受器细胞、脊椎动物视网膜内广泛的细胞类型以及大脑皮层、后脑和脊髓的神经元等多种系统中，环境在细胞命运决定和维持中的重要性已得到明确证实。细胞标记技术的进展，包括荧光染料和逆转录病毒标记，使得能够追踪正常和异型环境中细胞的命运，并证明了许多系统中祖细胞群体最初的可塑性。最近建立的用于研究神经发育的体外系统应能进一步明确那些决定和维持细胞命运的环境信号的确切性质和特征。当然，细胞身份的确立仅仅是成熟神经系统形成的初始阶段。一旦单个细胞的命运得以确定，细胞向合适位置的迁移、轴突向合适靶点的延伸以及神经回路的精细化就必然会发生。对线虫中影响这些过程的基因的定义以及成像技术的最新进展，为观察“活体”脑片中这些后期的动态过程提供了一种手段，有望显著推进对功能性神经系统发育复杂性的理解。
