RECONSTITUTION OF METACHRONAL WAVES IN CILIATED CORTICAL SHEETS OF PARAMECIUM .2. ASYMMETRY OF THE CILIARY MOVEMENTS

In conditions in which ciliated cortical sheets prepared from detergen t-extracted Paramecium multimicronucleatum cells adhered to glass cove rslips on a microscope stage, perfusion of a reactivation medium conta ining ATP plus cyclic AMP or cyclic GMP generated metachronal waves. A n analysis of the ciliary movements that generate these metachronal wa ves yielded the following results. During the generation of metachrona l waves, there were phase differences in the ciliary orientation of ad jacent cilia in the direction of wave propagation. Addition of cyclic AMP or cyclic GMP increased the rotational angular velocities during t he effective stroke of ciliary beating, but did not increase the rotat ional angular velocity of the recovery stroke. When the ATP concentrat ion in the cyclic GMP reactivation medium was increased, the rotationa l angular velocity during the effective stroke rose steeply and satura ted at 0.8 mmoll(-1) ATP, whereas that during the recovery stroke rose gradually. Addition of cyclic nucleotides caused a single cilium isol ated from neighbouring cilia on the cortical sheet to incline almost p arallel to the cortical surface during the recovery stroke. Addition o f cyclic GMP increased the amplitude of bending of cilia detached from the cortical sheet. From these results, it was concluded that increas es in the asymmetrical movement of individual cilia, caused by the add ition of cyclic nucleotides, create the ciliary interaction that gener ates the metachronal waves.