THE "CNIDOBLAST" AS AN EXCITABLE SYSTEM

Abstract

It seems established by now that nettling response as it is given normally by cnidarian nematocysts belongs to a rather standard type of physiological excitation event, though there is still some question about the functional significance of the morphological "cnidoblasts". It is instructive to consider this subject in comparison with that of muscle contraction response provided that one adopts the view of "post-energization" rather than that of "pre-energization". One of the centers of interest is at present in identification of coupler agent that mediates between the external excitation event and internal explosion event. For this problem, the experimentation with isolated nematocysts are of critical role. It was shown that apparently inconsistent situations are to be found even among the same type of cnida from closely related species, and it is interesting to see how one can negotiate such diversions to bring them into fundamental uniformity. Efforts so far made revealed us that there is still need for studying somewhat intricated interrelationship between, water, anions, and cations as to triggering of the isolated cnidae. Such study may lead to an understanding of the mode of operation of cnidae in situ in the normal response system. The discussion extends further to include the problem of remote control of nematocyst discharge.