Frequency of ciliary beat measured with a photo-sensitive cell.

Abstract

A REVIEW of the present knowledge of cilia has been made by Rivera1. Various methods have been used for estimating the frequency and testing the effects of different substances on ciliary beat. A common method has been to drop particles such as coal and seed on ciliated epithelium and to count the time required for the particle to travel a certain distance2. This method gives a rough value for the speed of the cilia, but other factors such as viscosity and thickness of the mucous layer interfere severely with the results. The ‘Flimmeruhr’3 and the ‘Cilioscribe’4 were other methods described by earlier authors. With the aid of the Leitz Ultra-Pak vertical light microscope better measuring methods have been developed. Cinematographic recording and stroboscopy combine greater accuracy with less traumatic effect on the cilia when measuring. Dalhamn examines the two methods systematically5and describes a cinematographic equipment which makes it possible to determine quite small changes in frequency of ciliary beat in living rabbits6. The strobosoopic method is rather severely criticized and not recommended by this author. Microscopic counting of the vibratory activity of small ciliated epithelium fragments in tissue cultures is another method which has been used for testing the influence of various agents7. A disadvantage of the cinematographic method is that the results are not available immediately, and, as continuous measurement is not possible, minor effects of substances tested might be overlooked.