This book covers cell-cell channels at all levels of biological organization. The purpose of this book is to document that cells are not physically separated and fully autonomous units of biological life as stated by the currently valid Cell Theory. If not the cell then some lower level unit must fulfill this role. The book deals also with the identity of this elusive unit of biological life.

he biological sciences are dominated by the idea that cells are the functionally autonomous, physically separated, discrete units of life. TThis concept was propounded in the 19th century by discoveries of the cellular structuring of both plants and animals. Moreover, the ap parent autonomy of unicellular eukaryotes, as well as the cellular basis of the mammalian brain (an organ whose anatomy for a long while defied attempts to validate the idea of the cellular nature of its neurons), seemed to provide the final conclusive evidence for the completeness of *cell theory', a theory which has persisted in an almost dogmatic form up to the present day. However, it is very obvious that there are numerous observations which indicate that it is not the cells which serve as the basic units of biological life but that this property falls to some other, subcellular assemblage. To deal with this intricate problem concerning the fundamental unit of living matter, we proposed the so-called Cell Body concept which, in fact, devel ops an exceedingly original idea proposed by Julius Sachs at the end of the 19th century. In the case of eukaryotic cells, DNA-enriched nuclei are intimately associated with a microtubular cytoskeleton. In this configuration—as a Cell Body—these two items comprise the fundamental functional and struc tural unit of eukaryotic living matter. The Cell Body seems to be inherent to all cells in all organisms.

Ion channels allow us to see nature in all its magnificence, to hear a Bach suite, to smell the aroma of grandmother's cooking, and, in this regard, they put us in contact with the external world. These ion channels are protein molecules located in the cell membrane. In complex organisms, cells need to communicate in order to know about their metabolic status and to act in a coordinate manner. The latter is also accomplished by a class of ion channels able to pierce the lipid bilayer membranes of two adjacent cells. These intercellular channels are the functional subunits of gap junctions. Accordingly, the book is divided in two parts: the first part is dedicated to ion channels that look to the external world, and the second part is dedicated to gap junctions found at cell interfaces. This book is based on a series of symposia for a meeting on ion channels and gap junctions held in Santiago, Chile, on November 28-30, 1995. The book should be useful to graduate students taking the first steps in this field as well as a reference for the aficionado. The aim of the meeting was mainly to show the impact of various modern techniques, including cell biology, molecular biology, biophysics, and molecular genetics techniques in the study of these ubiquitous intrinsic membrane proteins. Molecular-genetics techniques paved the road to the manipulation of the channel forming molecules.

Piezo Channels, Volume 79, the latest volume in the Current Topics in Membranes series provides the necessary membrane research to assist readers in discovering the current state of a particular field and future directions. New chapters in the updated volume include A Tour de Force: The Discovery, Properties, and Function of Piezo Channels, Piezo1 Channels in Vascular Development and the Sensing of Shear Stress, the Origin of the Force: The Force-From-Lipids Principle Applied to Piezo Channels, Genetic Diseases of PIEZO1 and PIEZO2 Dysfunction, and The Structural Basis for Sensing by the Piezo1 Protein. Users of this series will find an up-to-date presentation of the current knowledge in the field of Piezo Channels. Written by leading experts in the field Contains original material, both textual and illustrative, that make it a very relevant reference Presented in a very comprehensive manner Ideal reference for both researchers in the field and general readers who will find this book to be relevant and up-to-date

Interdisciplinarity is more often invoked than practised. This is hardly surprising, considering the daunting vastness of modern biology. To reach a satisfactory understanding of a complex biological system, a wide spectrum of conceptual and experimental tools must be applied at different levels, from the molecular to the cellular, tissue and organismic. We believe the multifaceted regulatory interplay between integrin receptors and ion channels offers a rich and challenging field for researchers seeking broad biological perspectives. By mediating cell adhesion to the extracellular matrix, integrins regulate many developmental processes in the widest sense (from cell choice between differentiation and proliferation, to tissue remodeling and organogenesis). Rapidly growing evidence shows that frequent communication takes place between cell adhesion receptors and channel proteins. This may occur through formation of multiprotein membrane complexes that regulate ion fluxes as well as a variety of intracellular signaling pathways. In other cases, cross talk is more indirect and mediated by cellular messengers such as G proteins. These interactions are reciprocal, in that ion channel stimulation often controls integrin activation or expression. From a functional standpoint, studying the interplay between integrin receptors and ion channels clarifies how the extracellular matrix regulates processes as disparate as muscle excitability, synaptic plasticity and lymphocyte activation, just to mention a few. The derangement of these processes has many implications for pathogenesis processes, in particular for tumor invasiveness and some cardiovascular and neurologic diseases. This book provides a general introduction to the problems and methods of this blossoming field.