- 1. Periodic oscillations were detected in the activity of single macromolecules: potassium channels. 2. When potassium channels are repeatedly activated in isolated patches from fused synaptosomes of Torpedo electric organ, their behavior exhibits a departure from random activation. 3. The departure from random behavior is demonstrated by the runs test and by the lack of fit to Poisson distribution. 4. Under appropriate experimental conditions, the channels display periodic oscillations with a periodicity of approximately 20 s when activated at a rate of 1.25 Hz. 5. The oscillations do not arise from sampling, recording, or computational artifacts. 6. It is conceivable that single-channel oscillations play a role in the generation of membrane oscillations and thus may contribute to the oscillatory behavior of the nervous system.