. The biology of cilia and flagella. Cilia and ciliary motion; Flagella (Microbiology). 194 CO-ORDINATION OF BEAT swimming of Opalina, and it appears that the wave pattern changes virtually instantaneously over the whole body. Increasing excitation causes a progressive change in the wave pattern, as shown in stages I to VI in Fig. 53, until the waves travel forwards from the posterior end. The change in direction of beat and the increase of excitation were found by Kinosita (1954) to be accompanied by an increased depolarization of the surface membrane of the animal. In a recent review of this
. The biology of cilia and flagella. Cilia and ciliary motion; Flagella (Microbiology). 194 CO-ORDINATION OF BEAT swimming of Opalina, and it appears that the wave pattern changes virtually instantaneously over the whole body. Increasing excitation causes a progressive change in the wave pattern, as shown in stages I to VI in Fig. 53, until the waves travel forwards from the posterior end. The change in direction of beat and the increase of excitation were found by Kinosita (1954) to be accompanied by an increased depolarization of the surface membrane of the animal. In a recent review of this subject, Kitching (1961) has suggested that the progressive depolarization of the surface membrane changes the site of pacemaker activity from the anterior end along c. Stage// Stage I Stage II Sta^e III Stage IV Stage V Stage yi Stage 1/1/ Fig. 53. Metachronal wave patterns at various stages in the reversal of ciliary beat in Opalina. The arrows on the figures indicate the direction of metachronal wave movement. The wave patterns on the ventral surface were observed through the transparent protoplasm (from Okajima. 1953). the " right " side of the body in transverse beating to the posterior end in reversed beating. Indeed, Okajima (1953) implies that the frequency of beat increases with increased excitation, and this would allow different pacemakers to control the beating activity of the cilia by their higher rate of stimulation. However, the direction of beat of cilia on a small area of the body surface is changed by a localized depolarization under conditions where the main pacemakers of the body (if these exist) are not affected at all. This leads to the alternative suggestion that the depolariza- tion of the surface membrane affects every cilium, not just the pacemaker, so that the direction of beat of every cilium is changed by a greater or lesser extent according to the amount of. Please note that these images are extracted from scanned page images that may ha
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