Voltammetric measurement of oxygen in single neurons using platinized carbon ring electrodes.

Naflon-coated ultrasmall platinum ring electrodes have been implanted in the giant dopamine neuron of the pond snail Planorbis corneus, and the oxygen concentration inside these single neurons has been estimated. Experimental data suggest that the intracellular oxygen level in the identified dopamine neuron of P. corneus is approximately 0.032 mM. The oxygen concentration immediately outside the cell (ca. 10 microns away from the cell) is 0.041 mM. Furthermore, staircase voltammetry can be used to monitor dynamic changes in oxygen concentration inside the cell after bathing with Ringer's solution saturated with air/oxygen. Data obtained for intracellular oxygen concentrations suggest that intracellular oxygen consumption is increased following potassium chloride-induced stimulation of these cells.