In July of 1989 the 31. International Congress of Physiological Sciences was held in Helsinki. This event in Finland gave us a chance to organize and maintain a satellite symposium on problems of epilepsy from July 4th to 8th, 1989, in Frankfurt-Main. In order to reduce the number of satellite symposia outside of Finland, the president of the IUPS asked different national committees to organize joint meetings. Previously, Dr. Mare~ and Dr. Rokyta had planned to organize a symposium on developmental aspects of epilepsy in Prague, while a meeting in Frankfurt had been planned as an update of a former satellite symposium on physiology and pharmacology of epileptogenic phenomena, held here in 1980. However we were able to combine our efforts by organizing one satellite symposium in Frankfurt entitled: 'PHYSIOLOGY, PHARMACOLOGY and DEVELOPMENT of EPILEPTOGENIC PHENOMENA'. Scientists are generally disappointed about the slow progress in knowledge of their field. We found that by comparing the outcome of the two symposia in 1980 and 1989 a remarkable progress in different, some completely new aspects of the field of experimental epileptogenesis could be realized. Also the new interest in the development of the brain contributed enormously to our understanding of the mechanisms underlying epileptogenic phenomena. We would like to thank all of our colleagues who accepted our invitation to present their recent data and for sending us their manuscripts.