Correlation of electrical and mechanical responses in nervous control of cilia

Abstract

ALTHOUGH cilia have many important functions in the majority of animal phyla, our knowledge about the mechanism by which their activity is controlled has been fragmentary¹. Extensive electrophysiological studies of the ciliated cell, with intracellular microelectrodes, have been made only with the relatively large protozoans, principally Paramecium, where the ciliary activity has been shown to be closely associated with the electrical properties of the cell membrane^2,3. Among the metazoans, some examples of nervous control of ciliary activity have been reported⁴, but, mainly because of technical difficulties, intracellular recording of the membrane potential from the ciliated cells has been made in only a few cases^5,6; in no case has nervous control of cilia been studied by recording simultaneously the electrical and the mechanical events. Such recording is essential to understanding the mechanism of nervous control at the cellular level.