https://science.sciencemag.org/content/sci/150/3699/971.full.pdf

Pain mechanisms: a new theory.

Impulses and Physiological States in Theoretical Models of Nerve Membrane

Pain mechanisms: A new theory

Identification of a novel force-generating protein, kinesin, involved in microtubule-based motility

https://www.cell.com/cell/pdf/S0092-8674(03)00111-9.pdf

The Molecular Motor Toolbox for Intracellular Transport

A VERTEBRATE motor nerve fiber is thickly covered with a layer of myelin sheath except at narrow gaps called nodes of Ranvier. As the myelin sheath is shown to be composed of an electric insulator, investigation of the physiological properties of these nodes seems to disclose the nature of the plasma membrane of an infinitesimal dimension and consequently to enable us better to understand the activity of the surface layer of a cell in general. The present investigation is undertaken to secure a series of oscillograms which seemed to us to indicate the basic properties of the plasma membrane at the nodes. The temporal configuration of the electric responses and the latencies of the responses to rectangular current pulses are our main concern in this paper.

Response of single Ranvier nodes to electrical stimuli.

From a biochemical point of view, the membrane of an electrically excitable cell, such as squid axon membrane, does not seem to be fundamentally different from that of other biological cells. When various proteolytic enzymes are applied to the axonal membrane from inside by the internal perfusion technique, the ability of the axon to produce action potentials is suppressed within a short period of time.l Similarly, the axon excitability can be eliminated by internal application of phospholipase A (probably also by phospholipase C) . Although the effects of externally applied proteases and lipases are somewhat equivocal,2*:L there is no doubt that the membrane is a macromolecular complex composed of proteins and phospholipids. Bioelectric phenomena observed in squid axons must then be electrochemical manifestations of physicochemical processes that occur in this macromolecular complex. If the axon membrane is to perform the normal function of producing action potentials, the presence of a different class of chemical components, namely ions, is essential. It is well known '-'; that alkali earth-metal ions, calcium ions in particular, are indispensable. The presence of univalent cations and the absence of divalent cations in the axon interior are also essential to the maintenance of excitability. Thus, in dealing with the process of nerve excitation, we are concerned with various types of interplay between these two classes of essential components, ions and macromolecules. It should be noted in this connection that the electrochemical processes that maintain the normal distribution of ions across the membrane (ion pumps) are not directly related to the process of nerve excitation; these processes will not be discussed in this Paper. It is well known that the conformational states of various macromolecules are strongly affected by the ions in the medium.7, Changes in the conformational state can, in turn, influence the mobilities and selectivities of the ions in the macromolecules. When the concentrations of multivalent cations or hydrogen ions in the macromolecules change, the effective fixed charges of the macromolecules are expected to be altered.!' These changes in membrane macromolecules invariably lead to an alteration of the membrane potential (if the membrane current is maintained at zero) or of the membrane current (if the membrane potential is fixed). The objective of this paper is to analyze the process of such interplay between ions and the membrane macromolecules on the basis of a large number of experimental facts, accumulated mainly during the past decade. In analyzing this interplay between ions and the membrane macromolecules,

Energy transduction in the nerve membrane and studies of excitation processes with extrinsic fluorescence probes.

The fluid flowing by the Nitella internode or squid giant axon loaded with radioactive cations was fractionated during the action potential. In this manner it was possible to ascertain the time course of efflux of these cation tracers during activity

Ichiji Tasaki

Papers

Response of single Ranvier nodes to electrical stimuli.

Energy transduction in the nerve membrane and studies of excitation processes with extrinsic fluorescence probes.

Fractionation of Tracer Effluxes during Action Potential.

Excitation of single nerve fiber by action current from another single fiber

Depolarization induced change in the enzymatic radio iodination of a protein on the internal surface of the squid giant axon membrane