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K Onodera

Publications and source records attributed to K Onodera.

At least 433 records · Page 24Linked to original sources
PubMed1969

Membrane properties of the stretch receptor neurones of crayfish with particular reference to mechanisms of sensory adaptation.

1. Membrane properties of neurones of the two morphologically different types of stretch receptor of crayfish, the slowly adapting (RM(1)) and the rapidly adapting (RM(2)) receptors, were investigated with two microelectrodes inserted into the same neurone.2. The action potential was usually larger in the slowly adapting than in the rapidly adapting neurone. But the distributions of the height were not sharply delimited, and there was an overlap from the two groups of neurone.3. There were no marked differences in the current-voltage relationship between the two types.4. Under voltage clamp, depolarizations evoked a large delayed outward current, which slowly diminished during maintained depolarization (K-inactivation). Under a moderate depolarization, development of the K-permeability increase was very slow.5. When stimulated by intracellularly applied constant currents, the slowly adapting neurone always adapted slowly, and gave rise to long-lasting trains of spikes, whereas the rapidly adapting neurone never produced maintained repetitive discharges.6. The same marked differences in the adaptation behaviour of spike discharge between the two types were also observed when the neurones were stimulated by constant currents applied through external electrodes.7. When the stimulating point was shifted along the axon of the slowly adapting neurones, the ability to produce long-lasting repetitive discharges was found to be confined to the axonal region near the soma, where the diameter was very small, and where impulses were first initiated.8. Possible ionic mechanisms of the adaptation of the spike generating membrane were discussed. The importance of slowly occurring changes in the Na- and K-permeabilities and changes in the electromotive force of the membrane due to electrogenic pump was emphasized.

Action Potentials↗
PubMed1969

Adaptation of the generator potential in the crayfish stretch receptors under constant length and constant tension.

1. Generator potentials were investigated in stretch receptors of crayfish after abolishing spike potentials with tetrodotoxin.2. The time courses of the decline of generator potential (generator adaptation) were almost the same in the slowly and rapidly adapting receptors.3. The time courses of the tension changes after suddenly stretching the receptor muscles did not differ much between the two receptor types.4. The amplitudes of generator potential per unit stress or per unit strain in the receptor muscle were roughly the same in the two receptor types.5. By comparing generator adaptation under length-clamp and tension-clamp in the slowly adapting receptors, it was suggested that roughly 70% of the generator adaptation could be explained by a simple visco-elastic property of the receptor muscle, when observed for 1 sec after the beginning of the stretch.6. It was concluded that the marked differences in the receptor adaptation between the two receptor types were attributable to the differences in the properties of spike generating membrane rather than to the properties of the generator potentials.7. In each type of receptor, both the generator adaptation and the adaptation of spike generating mechanisms contributed to determining the whole rates of receptor adaptation. In the slowly adapting receptor, however, the generator adaptation seemed more important, while in the rapidly adapting receptor the spike generating mechanisms seemed more important.

Adaptation, Physiological↗