Neurobiologists are bound to differ in their perceptions of what the discipline of molecular neurobiology should encompass. We have taken the view that molecular neurobiology should cover any aspect of brain science that uses the techniques of modern molecular biology, though we accept the fact that classification of a technique as a "biochemical* or "molecular biological* one is in itself somewhat arbitrary. Each chapter of this volume sets out to identify a clear problem in neurobiology and to place it in its context within the literatu- i.e., indicating how the solution of the problem will advance knowledge in the field. The core of the chapter then details the approaches taken to solve the problem, in sufficient detail that the reader can appre- ate exactly why a specific strategy was adopted and how it was executed. Each chapter also includes detailed protocols providing all the inf- mation necessary to reproduce the technique and its results in any appropriately equipped laboratory.