![]() ![]() Bullock (1945) found that when the nerve cord is stimulated in this way a single shock of sufficient intensity will evoke a single impulse in the median and lateral giant fibres. The preparation eventually used was set up as follows: the anterior end of the worm was pinned down, ventral surface uppermost, and the giant fibres were stimulated by inserting a pair of fine platinum electrodes, insulated almost to the tip, on to the nerve cord through the mid-ventral body wall. Apart from this no information is available on the muscular responses mediated through the giant fibres in oligochaetes.ĭifficulty was encountered in making a reliable nerve-muscle preparation which was not suspected of suffering from post-operative fatigue. ![]() ![]() He also presented evidence that the longitudinal contraction is accompanied by simultaneous contraction of the circular muscles. Von Holst (1932) found that the giant fibres can mediate a rapid response which need not necessarily occur over the entire length of the body but may be confined to the anterior end. ![]() Botsford (1941) and Wu (1939) concluded that the neuromuscular apparatus of the earthworm is cholinergic. Straub (1900), Budington (1902) and Botsford (1941) investigated the physiological properties of the longitudinal musculature of Lumbricus, but the preparations which they used were such that it would not be possible to say whether the responses obtained were produced through the giant fibres or through some other constituents of the nervous system. Apart from observations on the genesis of tetanus, etc., in the sabellids Branchiomma ( Nicol, 1951) and Myxicola (Roberts, 1962 b) no work has been done on the muscular responses mediated through the giant fibres in polychaetes. ![]()
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