Abstract: Many kinds of insects have developed resistance to all known classes of pesticides. Ion channels are the primary targets for several classes of natural and synthetic insecticides. The rapid development of electrophysiology and molecular biology during recent years have greatly facilitated the study of ion channels at cellular and molecular level. The principal members of the family of voltage-dependent channels are those selective for sodium, potassium, and calcium. The activities of all the channels of a cell can be monitored in voltage- and patch-clamp studies. Voltage and patch-clamp techniques allow direct measurement of voltage-dependent activation, voltage-dependent inactivation and selective ion transport of voltagesensitive ion channels. They can also demonstrate effects of pesticides on specific ion channels in excitable membrane. Patch-clamp technique allows more detailed analysis of many kinds of insecticides modification of ion currents at the whole-cell and single-channel level. In the nervous system, ion channels are involved in sensory transducting, signal propagation, and processing. These properties of channels can be altered by many kinds of pesticides. Electrophysiological, isotopic flux methods, and microfluorometric determination provide an alternative approach to estimation of insecticides on the ion channels. A substantial number of electrophysiological investigations had been carried out on insects with resistance factors. This paper summarized the information on electrophysiological techniques involved in insects resistance studies and insecticides selection.

Key words: electrophysiology, voltage-clamp, patchclamp, insect resistance, pesticide