ISSN:
1432-1351
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Medicine
Notes:
Summary 1. Paramecium bursaria was stimulated by a light spot of 10–15 μm diameter, and the photosensitive site was searched by recording responses in swimming behavior and in membrane potential. 2. Local stimulation to the anterior half of the cell caused an avoiding response. 3. Stimulation to the cells deciliated by ethanol treatment elicited a depolarization of the membrane potential. 4. Local stimulation to the anteroventral portion elicited a depolarization, but stimulation to the dorsal side induced no change in the membrane potential. 5. The action spectrum of depolarization elicited by local stimulation to the anteroventral surface showed two main peaks at 420 nm and 560 nm, corresponding to those of light stimulation of the whole cell. 6. It is concluded that a photosensitive site exists on the anteroventral surface ofParamecium, in particular within the oral groove of the cell. This local photosensitivity is discussed with respect to the mating reaction.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00610995
