Spectral characterization of ciliary beating. Temperature dependence on spectral parameters

Ciliary beating was optically examined in tissue cultures from frog palate epithelium. Consecutive segments of the analog signal were Fast- Fourier transformed. The three main parameters which define the spectrum, position of the peak maxium (f), width of the spectral line (S.D.), and area (A) under the spectrum, were all measured as a function of temperature. These measurements were also examined as a function of the number of cilia by varying the examined area from 1.2 to 122 μm². It was found that: (a) all the parameters were exponentially temperature dependent; and (b) the average frequency was independent of the number of cilia examined, while S.D. was dependent on it. On a physiological level, we demonstrated that the ciliary fluctuation in frequency is temperature dependent, increasing with increase in temperature. Moreover, it was shown that where a relatively small number of cilia were measured (d = 1. 24 μm), the area A under the observed spectrum was directly proportional to the amplitude of ciliary beating. Increasing the temperature decreases the amplitude and vice versa. According to our suggested model the dependence of A on f was predicted and verified experimentally. A mathematical model which simulates the S.D. as a function of examined area and temperature is suggested. The calculated results from the model are in a good agreement with our experimental findings.