Ionic Basis of Membrane Potential and of Acetylcholine-evduced Currents in the Cell Body of the Cockroach Fast Coxal Depressor Motor Neurone
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چکیده
The ionic basis of the resting potential and of the response to acetylcholine (ACh) has been investigated in the cell body membrane of the fast coxal depressor motor neurone in the metathoracic ganglion of the cockroach Periplaneta americana. By means of ion-sensitive microelectrodes, intracellular concentrations of three ion species were estimated (mmoll"): [K]j, 144±3; [Na]j, 9±1; [Cl~],, 7±1. The resting potential of continuously superfused cells was -75.6±1.9mV at 22C. A change in resting potential of 42.0±2.5mV accompanied a decade change in [K]o. Experiments with (10~ molP) ouabain, Na injection, low temperature (10°C) and non-superfused cells indicated the presence of an electrogenic sodium pump.
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