Disruptive effects of electroconvulsive shock as a function of current level and mode of delivery.

Abstract

Mice from two strains were tested on a passive avoidance situation at several levels of foot shock. Electroconvulsive shock at current levels from 5-80 ma. was applied within 10 sec. of foot shock via one of four procedures: Eyes-cup-shaped electrodes were applied to each eye; Ears-spring pressure clips were attached to the ears; Cross-a spring clip was attached to the left ear and a cup electrode applied to the right eye; Same-a spring clip was attached to the right ear and a cup electrode applied to the right eye. The mode of delivery, the ECS current level, and the footshoek intensity interacted to determine the amount of disruption exhibited when the animal was tested 24 hr. later. The amount of disruption was inversely related to the resistance of the path between the two electrodes.

Memory storage: Evidence that consolidation continues following electroconvulsive shock

“…Ray and Barrett (1969), Jarvik and Kopp (1967), Dorfman and Jarvik (1968) and Lee-Teng (1969) have all found that with increases in the intensity of the electroshock current there is a corresponding increase in the amount of interference with retention. The only exception to this general pattern of results is an earlier experiment of Weissman (1963) which did not observe an increase in retrograde amnesia following large increases in the ECS current intensity.…”

Modification of Memory Storage Processes

“…The RA gradient observed has been shown to depend upon several factors including the nature of the current (Alpern C ! McGaugh, 1968;Dorfman CE Jarvik, 196%;Miller, 1968), as well as the route of application (Dorfmnn & Jarvik, 196Sb; Ray & Barrett, 1969) and the time of day at which the treatment is given (Stephens, McGaugh Stephens R: AIcGaugh, 1968b). Clearly, under these restricted conditions RA curves have been shown to be curves of susceptibilit,y, not curves of consolidation.…”

The effect of hyperthermia on memory in rats

“…The amount of memory impairment, for example, is directly related to the depth of body temperature reduction (Riccio et al, 1968). Similarly, the more intense the electroconvulsive shock (Hughes, Barrett, & Ray, 1970;Ray & Barrett, 1969;Weissman, 1964) or the greater the duration of etherization (Herz, Peeke, & Wyers, 1966), the greater is the memory loss. The purpose of this experiment was to see if…”