Rapid advances in knowledge have led to an increasing interest in neuro­ biology over the last several years. These advances have been made possible, at least in part, by the use of increasingly sophisticated methodology. Furthermore, research in the most rapidly advancing areas is essentially multidisciplinary and is characterized by contributions from many investi­ gators employing a variety of techniques. While a grasp of fundamental neurobiological concepts is an obvious prerequisite for those who wish to follow or participate in this field, critical awareness and evaluation of neurobiological research also requires an understanding of sophisticated methodologies. The objective of Methods in Neurobiology is the development of such critical abilities. The reader is exposed to the basic concepts, principles, and instrumentation of key methodologies, and the application of each meth­ odology is placed in the special context of neurobiological research. The reader will gain familiarity with the terminology and procedures of each method and the ability to evaluate results in light of the particular features of neurobiological preparations and applications.