With the discovery of an ever increasing number of biogenetic polypeptides in the autonomic nervous system, it is evident that nervous transmission is controlled and modified not only by a series of classical transmitters but also by a variety of co-transmitters and modulators. Purifi cation, characterization and synthesis of neuropeptides and peptide families allows the application of specific anti bodies for radioimmunological, immunohistochemical and immunocytochemical localization. Transmitter interactions and phenotypic neuronal plasticity can be analyzed by pharmacological or surgical manipulations. Biochemical and autoradiographic determination of specific membrane receptors enables the recognition of peptide target struc tures. In addition, neurophysiological techniques in combi nation with histochemical methods result in functional interpretations. With regard to somatic manifestations of autonomic nervous disturbances these studies will offer fundamental insights for clinical medicine. This volume contains the refereed proceedings of recent investigations on histochemistry and cell biology of auton omic neurons and paraganglia which were presented at an international colloquium on nervous transmission in Heidelberg in September 1986. The colloquium was origi nally planned to be held under the presidency of Olavi Eranko but was continued by the editor after his death. It was sponsored by the German Research Foundation and took place on the occasion of the 600th anniversary of the Heidelberg University "Ruperto Carola" as part of the pro gram in the international "Wissenschaftsforum". Hopefully, the information provided in this book will stimu late new ideas and research strategies in the field of neu roscience.