In Neurotrophin Protocols, established leaders in the neurotrophin field detail their special expertise in a wide variety of key protein, RNA, recombinant, and in vivo techniques. The protocols range from immunological analysis for the cellular localization and quantification of the neurotrophins, to genetic manipulation of cells and animals for analysis of biological function, to quantitative analysis of the active neurotrophin genes. There are also radiotracing techniques for studying neurotrophin transport in both the retrograde and anterograde directions, procedures for using immunotoxins to study the effects of eliminating a single class of neurons, and the essential stereological method for estimation of neuronal numbers. Timely and robust, Neurotrophin Protocols provides today’s neuroscientists in both academia and industry with a comprehensive range of practical, readily reproducible methods for studying neurotrophins and the critically important effects they have on the nervous system.