ISSN:
0886-1544
Keywords:
high-speed microcinematography
;
Hemicentrotus
;
primitive response
;
ciliary reversal
;
Life and Medical Sciences
;
Cell & Developmental Biology
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Biology
,
Medicine
Notes:
Transient ciliary movement during responses to electric stimulation of embryos of the sea urchin, Hemicentrotus pulcherrimus, was analyzed in terms of angular direction with a time resolution of approximately 2 ms with high-speed microcinematography. In the primitive response, which can be induced only in the early stages of development of the embryo, bending transients always started with a short pause in the middle of the effective stroke, irrespective of beat position on stimulation. In the reversal response, induced only in the late stages of development, bending transients occurred with a delay as short as some 10 ms from stimulation, and with a transient sharp deviation from the normal beat before the cilium took the position of the beginning of the recovery stroke of the reversed beat. The delay was significantly shorter at the base than at the tip, suggesting that some form of signal travels along the cilium; the speed was ten times higher than that of propagating bends in the normal beat. These facts indicate that the sensitivity to internal changes resulting from stimulation of the axoneme may vary with development, ciliary beat positions, and regions along the cilium.
Additional Material:
7 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/cm.970070303
