That time coincided in the world neuroscience with the beginning and development of the era of microelectrode techniques, and Prof. Kostyuk was a pioneer in introducing these new experimental approaches in the Soviet Union and in opening up broad prospects in direct studies of intracellular electrical processes and cell-to-cell communication in the nervous systems. Principles of microelectrode techniques and first results of the studies of functional organization of the spinal cord obtained in the respective experiments were summarized by Prof. P.G. Kostyuk in the monographs "The two-neuronal reflex arc" (1959) and "Microelectrode technique" (1960), which became for many years the main manuals for research associates and postgraduate students working in the field of electrophysiology throughout the entire Soviet Union.