Since the identification of histamine in brain tissue in 1943 (Kwiatowski, 1943), there has been controversy over what role this compound may play in the central nervous system. Thus histamine in the brain has been proposed to be involved in the etiology of schizophrenia (see review, Green, 1964), Parkinson’s disease (Unger and Witten, 1963), temperature regulation (Shaw, 1971), motion sickness (Crossland, 1971), and migraine (Sjaastad and Sjaastad, 1970). It has even been proposed as a biochemical mechanism for the efficacy of acupuncture (Popkin, 1972). This controversy is undoubtedly due to methodological problems in the study of histamine, whose simple chemical structure does not have any useful physical or chemical properties that can be utilized for assay. This led to the development of sensitive bioassay and fluorometric techniques for the assay of histamine. Whereas these techniques were invaluable for the study of histamine in peripheral organs, their application to brain tissue was limited owing to their lack of specificity.