Search.

Arrangement for interference of excitatory waves—Effect of increasing difference of phase—Interference effects causing change from positive to negative, through intermediate diphasic—Diametric balance—Effect of unilateral application of KHO—Effect of unilateral cooling . ; - Iq! Different theories of current of injury—Pre-existence theory of Du Bois …

… Different theories of current of injury—Pre-existence theory of Du Bois- Reymond—Electrical distribution in a muscle-cylinder—Electro-molecular theory of Bernstein—Hermann’s Alteration Theory—Experiments demon- strating that so-called current of injury is a persistent after-effect of over- stimulation—Residual galvanometric negativity …

From these facts, that the dying is negativé, and the dead relatively positive to the living, it is clear that the so-called current of injury is liable to reversal. In the case of the former, the current of injury will be from the dying to the living …

… That it is this depression of excitability, and not the current of injury as such, which is the essential condition for obtaining resultant response, is seen from the fact that excitatory response may still be obtained, even when the so-called current of injury is zero, or reversed …

In another experiment, the specimen employed was a petiole of cauliflower (Brassica oleracea). ‘The first up-line to the right indicates the current of injury. The three re- sponses which succeed are induced by a given intensity of stimulus, the next series of six, being in response to …

Taking the first of these—that in which the injured contact is negative—the action-current, in response to stimulus, will bring about a negative variation of the so- called current of injury. In the second, the result will be indeterminate, since the injury-current is zero. In …

… Diffuse stimulation, inducing negativity at the uninjured A, causes a negative variation of the current of injury. Then the current of injury gradually subsides, with the result of disappearance of response by negative variation. By the method of injury, one end is made initially abnormal ; whereas by the …

… It is in general vaguely accepted that, in order to obtain a response by negative variation an‘antecedent current of injury is necessary, by whose induced variation we may be able to record responsive effects. In cases of the dis- appearance of the current of injury, it is …

… A current—the current of injury—is found to flow in the nerve, from the injured to the uninjured, and in the galvanometer, through the electrolytic contacts from the uninjured to the injured. As long as there is no further disturbance this current of injury remains approximately constant …

… Specimen originally isotropic (a) A, end slightly injured and negative; Cc, current of injury; R, action- current, a negative variation of Cc. (4) A, end killed and positive ; C, current of injury; R, action-current, a positive variation of c.

… a current of injury is produced, and the response at A is then observed as a negative variation of the current of injury. The injured tissue may, however, exhibit gradual recovery, on account of which the resultant response undergoes diminution or abolition. A fresh injury has therefore to …

reversed injury-current is represented as down, the subse- quent excitatory responses are also down, and constitute a positive variation of the current of injury. It will thus be seen that an identical excitatory reaction of the living tissue appears to give rise to directly opposite Fic. 116 …

… If this current of injury remained always invariable in direction—that is to say, from the injured to the uninjured—there would be no source of uncertainty. But it is often found, for example in the retina, that the current of injury undergoes a reversal, or is reversed …

… effect produced at A, the existing difference of potential may thus be reduced, with a consequent diminution of the current of injury. During stimulation, therefore, a nerve exhibits a negative variation. We may express this in a different way by saying that a ‘current of action’ was produced …

… The current of injury, Cc, is A> B, and the responsive current, Rk, is B- A, constituting a negative variation. But when A is killed, the current of injury C is B> A, the responsive current is also BA, constituting a positive variation (fig. 117, 0). Second —we …

… Compensator.—As the responses are on variation of current of injury, and as the current of injury may be strong, and throw the spot of ight beyond the recording surface, a potentiometer balancing arrangement may be used (fig. 9), by which the P.D.due Laie a ot …

… As to the confusion arising from our present terminology, we must remember that the term positive or negative is used with regard to a current of reference —the so-called current of injury. When the two galvanometric contacts are made, one with the cut end of the nerve …

… Electrical Distribution in Plant-cylinder with Opposite Ends Sectioned The Current of Injury is simply therefore an excitatory after-effect, due to incomplete recovery from over-strain. But even after strong stimulation a slow recovery may occur, and the Current of Injury will thus undergo a progressive diminution …

(6) The end B injured; current of injury from B to A: stimulation gives rise to an action current from A to B. irresponsive. In that case, stimulus will cause greater electrical disturbance at the more responsive point, say A, and this will be shown by the galvanometer …

… We thus find three cases of the current of injury— the first being negative, the second zero, and the third positive.