The Construction of a Visual System
The work presented in this chapter concerns the development of the frog visual system, concentrating upon the specific connections which are formed between the retina and the primary visual center, the optic tectum. Topographic inter-connections between arrays of neurons, are commonly found in the vertebrate CNS and studies of their formation are thought to be central to our understanding of neural connectivity. The frog retinotectal projection, as an example of a topographically organized system, has been extensively used in such investigations. This system offers great advantages for developmental studies, since it continues to grow for many months, and throughout its development all parts of the system can be examined using a variety of methods of analysis. It is also possible to perform operations which perturb the system in a controlled fashion, either in the embryo, or at later stages when the regeneration of the retinal axons can be exploited. A further advantage, which arises naturally as a consequence of the extended period of growth of the system, is the continual and orderly alteration of the connections necessary for maintained function of the system during development.
KeywordsGanglion Cell Retinal Ganglion Cell Optic Tract Optic Tectum Retinal Ganglion Cell Axon
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