This volume derives from papers presented at the 4th biennial meeting of the Italian Biophysical Society, held in Parma in October 1979. It includes review lectures presented by guest scientists (R.H. Adrian, E. Neher, S. Ottolenghi, and G. Zaccai); the remaining reviews and papers present some of the problems currently under study in our country. One can see that biophysical problems are studied under differ­ ent academic roofs, i.e., at physiological or biochemical departments. We consider this a strength and a weakness at the same time. The "Italian Bioenergetics Group" contributed to the success of the meeting, as much as the groups working in various laboratories of the Consiglio Nazionale delle Ricerche, in particular those of the National Group of Cybernetics and Biophysics. To them, and to the University of Parma, which contributed financial and organiza­ tional support, the Editors of this volume wish to express their appreciation. Particular thanks are to Drs. E. Carbone and V. Lenci, who spent time and effort for the meeting and in collecting the papers. The special care in the typing goes to the credit of Miss Rampello, to whom the Editors express their deepest gratitude.