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I TASAKI

Publications and source records attributed to I TASAKI.

At least 19 recordsLinked to original sources
PubMed1964

INTRACELLULAR PERFUSION OF CHILEAN GIANT SQUID AXONS.

Axons of the Chilean giant squid were subjected to continuous intracellular perfusion with either potassium- or sodium-rich salt solutions. In axons immersed in natural sea water and internally perfused with potassium glutamate solution, action potentials which exceeded 160 millivolts were often observed. The resting potential did not vary appreciably with the internal concentration of potassium glutamate. With perfusing solutions containing sodium aspartate or sodium glutamate, action potentials were observed which exceeded the value calculated from the Nernst equation applied to sodium-ion activity. Nervous conduction could be maintained more than 1 hour with equal concentrations of sodium inside and outside the axon.

Action Potentials↗
PubMed1964

NEUROPHYSIOLOGY.

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Nerve Tissue↗
PubMed1963

Permeability of squid axon membrane to various ions.

The permeability of the squid axon membrane was determined by the use of radioisotopes of Na, K, Ca, Cs, and Br. Effluxes of these isotopes were measured mainly by the method of intracellular injection. Measurements of influxes were carried out under continuous intracellular perfusion with an isotonic solution of potassium sulfate. The Na permeability of the resting (excitable) axonal membrane was found to be roughly equal to the K permeability. The permeability to anion was far smaller than that to cations. It is emphasized that the axonal membrane has properties of a cation exchanger. The physicochemical nature of the "two stable states" of the excitable membrane is discussed on the basis of ion exchange isotherms.

Animals↗
PubMed1959

Voltage clamp behavior of iron-nitric acid system as compared with that of nerve membrane.

The current-voltage relation for the surface layer of an iron wire immersed in nitric acid was investigated by the voltage clamp technique. Comparing the phase of nitric acid to the axoplasm and the metallic phase to the external fluid medium for the nerve fiber, a striking analogy was found between the voltage clamp behavior of the iron-nitric acid system and that of the nerve membrane. The current voltage curve was found to consist of three parts: (a) a straight line representing the behavior of the resting (passive) membrane, (b) a straight line representing the fully excited (active) state, and (c) an intermediate zone connecting (a) and (b). It was shown that in the intermediate zone, the surface of iron consisted of a fully active patch (or patches) surrounded by a remaining resting area. The phenomenon corresponding to "repetitive firing of responses under voltage clamp" in the nerve membrane was demonstrated in the intermediate zone. The behavior of the cobalt electrode system was also investigated by the same technique. An attempt was made to interpret the phenomenon of initiation and abolition of an active potential on the basis of the thermodynamics of irreversible processes.

Iron↗