Role for spontaneous neural activity in the patterning of connections between retina and LGN during visual system development

One of the most remarkable features of the adult nervous system is the precision of wiring, as if nothing has been left to chance. How do precise neural connections form during the development of the mammalian brain? One idea is that the brain wires itself up like a computer. That is, chips and components are assembled and connected according to a preset circuit diagram, and then with a flip of a switch, the computer turns on and works as it was designed. In the case of brain development, this analogy would imply that the brain only begins to work once it is essentially completely wired according to the adult pattern of connectivity. The main theme of this article is that the biology of brain development follows very different rules. Neural connections are formed in the brain at very early times in development, and often in an immature pattern of wiring that only grossly approximates the adult precision. In order for the adult pattern of connections to form, neural function is necessary. This requirement for brain function in order to obtain adult brain wiring is nowhere more essential than in the developing visual system. zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA