Extended time analysis of ciliary beat frequency

Patterns of change in ciliary beat frequency have been investigated and characterized through the application of signal pattern recognition techniques. The frequency patterns of rabbit tracheal ciliated cells in culture were examined utilizing a photomultiplier system and the signals digitized and converted by Fast Fourier Transform analysis to a fundamental frequency. Frequencies were updated at one second intervals. Data was gathered continuously from individual cells for 8.5 minute periods and displayed graphically on the CRT screen of a DEC LSI 11/03 computer. Individual ciliated cells were found to fluctuate within a 1 Hz range along a frequency baseline. Recurrent rapid increases in frequency, ranging from 2-11 Hz above baseline have been observed. Subsequent rate of return to baseline occured at a slower rate than increase. The duration of a single frequency fluctuation lasted from as short as 5.5 seconds to as long as 54 seconds from increase in frequency until return to baseline. These fluctuations in frequency create a signal which has both constant (baseline) and sinusoidal (peak) components. A mathematical model has been proposed to describe these components. The frequency fluctuations in an individual cell in a 8.5 minute period has been observed to vary from 0-17 Hz. Peak heights & widths were relatively constant within cells; variations between non~adjacent cells was substantial. Patterns of frequency fluctuation in adjacent cells also appear non-homogenous. Baseline levels of frequency were, in contrast, markedly similar for cells in close proximity. No doubt this constancy in the baseline frequency of beat for adjacent cells contributes to the integrity of metachronal waves.