Electric activity of non-excitable biological cells at radio frequencies

The importance of cellular electrical phenomena is well known. Most investigations have been limited to static and quasi-static effects. Very few studies deal with the occurrence of RF fields, which can be expected for theoretical reasons. Indirect evidence arises from microdielectrophoretic work that delivers information about the spatial distribution and temporal development of AC electric fields around biological cells. A more detailed investigation is possible by an electronic detection of these fields. A survey of both microdielectrophoretic and electronic work is given, together with some principles that are crucial for the design and interpretation of experiments. We present a multichannel frequency analysis system that for the first time allows the continuous monitoring of cellular RF activities over a wide frequency range. For the fission yeast Schizosaccharomyces pombe rhythmic signal changes with period lengths of about 400 s have been found that could be reproduced in a number of experiments.