The advent of polyclonal immunoglobin-based technology, originated by Yalow and Berson in 1959, for qualitative or quantitative determination of specific substances in biological tiβue has revolutionized the analytical aspects of biomedical research. The refinement of this technology by the application of monoclonal antibody (Mab) techniques that were pioneered by Kohler and Milstein (1975) increased the already numerous applications of the methodology. Consequently, the published information relevant to the relationship between immunology and neurobiology is of immense proportions. A comprehensive review of even a specialized area is difficult, and new methods are evolving so rapidly that any review is doomed to early obsolescence.