Configuration of intestinal slow waves obtained by monopolar recording techniques.

BQRTQFF, ALEX. ConJigur&n of intestinal slow waves obtained by monopolar recording techniques. Am. J. Physiol. 2 I 3 ( I > : I 57-162. I967* -This paper represents an attempt to analyze the configuration of the intestinal slow wave recorded from cat jejunum with extracellular monopolar electrodes. The “intermediate” form of the monopolar slow wave consists of an abrupt positive deflection followed by a negative notch and a more positive plateau that gradually subsides to the original potential level.. It is shown, first, by systematically altering the position of the recording electrode while monitoring interelectrode resistance, and second, by summating monophasic and electronically differentiated forms of the slow potential, that the intermediate form represents a combination of the propagated monophasic slow wave and its associated field potential. Which form predominates depends on the relative magnitude of the shunting resistance, R,, around the tip of the recording electrode. I f R, is large the monophasic form, representing the temporal course of membrane potential, predominates. As R, decreases, the field potential, representing the temporal course of membrane current, becomes predominant, Unless the time courses, polarities, and magnitudes of each of these components can be determined, the intermediate type of record cannot be interpreted in terms of electrical changes at the membrane level.