The patch clamp technique makes it possible to measure small electric currents (10^-13 A) induced by activation of ionic channels. It is possible to measure the currents from a set of ionic channels during synaptic current (whole-cell configuration), or from single ionic channels isolated in the membrane patch. The glass microelectrode is sucked to the surface of cellular membrane and connection with high electrical resistance („gigaseal“) is formed. See several possible configuration of microelectrode tip and the membrane in the picture A. Cell attached, inside-out and outside-out configurations enables to record currents through one or several ionic channels isolated in the membrane patch (Fig. B). In the whole-cell configuration is possible to measure currents from all channels present in the cell membrane. Several configurations of recording could be combined with rapid application of solutions for measurements of ion channels kinetics.