This monograph is dedicated to the anniversary of the birth of the great Ukrainian world-famous neurophysiologist, biophysicist Academician Platon Grigoryevich Kostyuk. The monograph includes sections written by P.G. Kostyuk and his students who worked directly with him in the department or defended dissertations under his supervision. The monograph was prepared for a long time, so some authors have already passed away, like Platon Grigoryevich himself. The monograph presents memoirs and scientific data of research in modern molecular, cellular and theoretical neurophysiology and biophysics. The chapters are presented mostly in chronological order of his students’ collaboration with Kostyuk. The monograph will be especially useful for specialists in neurophysiology, biophysics, and medicine: scientists, teachers, graduate students, and students involved in biology and medicine.