This book presents the papers that were delivered at the Satellite Symposium of the International Society for Neurochemistry in Padua, September, 1975. Having such Satellite Symposia was a new experiment for the Society, and all signs, including those from Padua, indicate that it was a very successful experiment, which will be an old tradition for the Society. The large international meeting affords the opportunity for presentations from all areas, for meeting of colleagues from various backgrounds and disciplines. The Satellite Symposia allow people from the same area of interest to discuss their subject in depth, and as such represent meetings of possibly the greatest practical significance for the partici pants. The Padua Symposium was no exception: all who particiDated in it could testify to its success in exchanging of information, learning of new approaches, and acqu~r~ng of new ideas, also the strengthening of old friendships, forming of new friendships and new collaborations, and exposing ideas to criticisms, suggestions, discussions. As a sign of the interest and success of the partici pants I can mention that all participants have sent in their contributions. Perhaps editors of volumes would anpreciate that the very last came in no later than two months past the deadline.