This volume on the processes of transformation of mechanical stimuli into electrical activity in various mechanoreceptors comprises the authors` investigations as well as relevant literature data. It deals mainly with initial electrical processes from stimulus of the mechanoreceptor to receptor potential. For the first time the connection between passive and active ion transport and the generation of electrical potentials is considered in detail. Furthermore, data on the properties and selectivity of different types of mechanosensitive ion channels, as well as results of morphological experiments on characteristics of the mechanosensitive membrane, and the changes during the activation of primary and secondary mechanoreceptors are discussed. This comprehensive overview is of interest to molecularbiologists, neuroscientists and biophysists.