Abstract
This chapter describes a specific case in which theory is extremely instructive and essential in illuminating a fundamental biological problem. The advent of gene microarray technology in the post-genomic era has sensitized many biologists to the need for new quantitative methods of all kinds as part of the analysis of complex biological systems in general, and neuroscience in specific. Thus, both the need for formal models to capture the dynamics of networks of molecules and neurons and the need for sophisticated statistical measures to extract meaning from multi-dimensional data sets have made experimental biologists more interested than ever before in the tools that can be provided by theory of all kinds. Neuroscience is today ideally poised to profit optimally from the influx of talented theorists. Today more than ever it is clear that theory is necessary to catalyze paradigm shifts in the way people pose problems about the nervous system. These paradigm shifts will occur when smart experimentalists and smart theorists find common language and common ground to reveal how the glorious richness and detailed idiosyncrasies of neurobiological systems contribute to their ability to be at the same time plastic and stable. It is not yet obvious how networks can learn and develop without losing their ability to function as they are changed.