In the past few years, the scientific community has witnessed significant progress in the study of ion channels. Technological advancement in biophysics, molecular biology, and immunology has been greatly ac celerated, making it possible to conduct experiments which were deemed very difficult if not impossible in the past. For example, patch-clamp techniques can now be used to measure ionic currents generated by almost every type of cell, thereby allowing us to analyze whole-cell and single channel events. It is now possible to incorporate purified ion channel components into lipid bilayers to reconstitute an "excitable membrane." Gene cloning and monoclonal antibody techniques provide us with new approaches to the study of the molecular structure of ion channels. A variety of chemicals have now been found to interact with ion channels. One of the classical examples is represented by tetrodotoxin, a puffer fish poison, which was shown in the early 1960s to block the voltage-activated sodium channel in a highly specific and potent manner.

'Further establishes the reputation of the series...an invaluable resource.' -Trends in Pharmacological Sciences, from a review of Volume 3 Volume 4 explores such emergent topics as: three-dimensional conceptions of ion channel proteins based on the available structural and functional data; the structure, pharmacology, and regulation of the GABAA receptors; and the Ca2+-dependent K+ channels in adrenal chromatic cell membranes.

'Further establishes the reputation of the series...an invaluable resource.' -Trends in Pharmacological Sciences, from a review of Volume 3 Volume 4 explores such emergent topics as: three-dimensional conceptions of ion channel proteins based on the available structural and functional data; the structure, pharmacology, and regulation of the GABAA receptors; and the Ca2+-dependent K+ channels in adrenal chromatic cell membranes.

In the past few years, the scientific community has witnessed significant progress in the study of ion channels. Technological advancement in biophysics, molecular biology, and immunology has been greatly ac celerated, making it possible to conduct experiments which were deemed very difficult if not impossible in the past. For example, patch-clamp techniques can now be used to measure ionic currents generated by almost every type of cell, thereby allowing us to analyze whole-cell and single channel events. It is now possible to incorporate purified ion channel components into lipid bilayers to reconstitute an "excitable membrane." Gene cloning and monoclonal antibody techniques provide us with new approaches to the study of the molecular structure of ion channels. A variety of chemicals have now been found to interact with ion channels. One of the classical examples is represented by tetrodotoxin, a puffer fish poison, which was shown in the early 1960s to block the voltage-activated sodium channel in a highly specific and potent manner.

A wealth of information has been accumulated about the function of ion channels of excitable cells since the extensive and pioneering voltage clamp studies by Hodgkin, Huxley, and Katz 36 years ago. The study of ion chan nels has now reached a stage at which a quantum jump in progress is antici pated. There are many good reasons for this. Patch clamp techniques origi nally developed by Neher and Sakmann 12 years ago have made it possible to study the function of ion channels in a variety of cells. Membrane ionic currents can now be recorded practically from many types of cells using the whole-cell patch clamp technique. The opening and closing of individual ion channels can be analyzed using the single-channel patch clamp method. Techniques have also been developed to incorporate purified ion channels into lipid bilayers to reconstitute an "excitable membrane. " Advanced tech niques developed in molecular biology, genetics, and immunology, such as gene cloning and the use of monoclonal antibodies, are now being applied to the study of ion channels. A variety of drugs have now been found or are suspected to interact with ion channels to exert therapeutic effects. In addition to the classical exam ples, as represented by local anesthetics, many other drugs, including cal cium antagonists, psychoactive drugs, cardiac drugs, and anticonvulsants, shown to alter ion channel function. For certain pesticides such as have been pyrethroids and DDT, sodium channels are clearly the major target site.

Intoxication of humans and animals has become increasingly important in recent years as has contamination of the environment by a variety of chemicals. In order to develop effective means by which such intoxication and contamination can be properly handled, it is imperative to know how these environmental agents act in humans and animals. Despite studies conducted by various investigators, the mechanisms of action of these environmental agents have not been fully elucidated. Insecticides are by no means an exception in terms of the seriousness of the problem and of the urgency of the need for such information. In order to complete a picture of the effects of any particular insecticide, it is of utmost importance that its actions at various levels ranging from those of molecules to whole animals be analyzed and synthesized. To understand the toxicological action on animals or humans, it is not sufficient to know the action at each level only. The actions at various levels must be integrated to construct a picture of the toxic effect on the intact organism. However, in spite of the large body of information that has been accumulated during the past few decades, little or no attempt has been made to integrate experimental data obtained at the molecular, cellular, organ, and animal levels together in order to define the whole picture of insecticidal action.