The scanning electron microscope (SEM) provides an ideal system for studying the three-dimensional surface structure of biological materials . Our previous work on the protozoan Opalina showed that instantaneous fixation, combined with critical point drying, faithfully preserved the pattern of ciliary coordination and the form of ciliary beat for scanning electron microscopy (1, 2) . I report h...

Our goal is to utilize microorganisms as micro-robots by using galvanotaxis (locomotor response to electrical stimulus). To reach this goal, observation of three-dimensional galvanotaxis must be achieved. Our group has proposed the technique for autofocusing cells by using the diffraction pattern that appears, which we call DepthFrom-Diffraction method. In this paper, we propose a novel three-d...

In Paramecium, secretory proteins are packaged within membrane-bounded vesicles in a condensed form. This form expands when the proteins are released. We have now determined that a proton gradient is present in the secretory vesicles of living Paramecium. Acridine Orange, used as an in vivo indicator of acidic compartments, stained the secretory vesicles in both wild-type and mutant cells. Addi...

The anticalmodulin drug, W-7 [N-(6 aminohexyl)-5-chloro-1-naphthalenesulphonamide] specifically inhibits the voltage-dependent Ca-current of Paramecium as well as the behavioural consequence of Ca2+ influx, backward swimming. The dechlorinated analogue, W-5, is four to five times less effective. Analysis of membrane currents under voltage clamp shows that W-7 not only reversibly inhibits the vo...

The effects of pulse laser irradiation on the cortex of Paramecium caudatum and Blepharisma undulans undulans were studied. The character and extent of cortical injury was video recorded and subsequently analyzed. Destruction of the cytoskeleton by laser irradiation was detected by immunofluorescence staining. A difference in the development and healing of the wound was observed between Paramec...