Passive avoidance behavior in rats after electroconvulsive shock: Facilitative effect of response retardation.

Abstract

Rats were trained in a one-trial passive avoidance task and then were submitted to electroconvulsive shock (ECS) or to sham ECS. Twenty-four hours later they were tested for retention,with the door opened either immediately or 30 sec after the beginning of the test. Rats initially forced to avoid for 30 sec continued to avoid for the entire test, but the others had the usual low step-through latencies seen withECS-treated animals. Activity measures for those animals stepping through differentiated groups having received footshock from those not having footshock and ECS. A retest 5-10 min later showed "recovery" in the amnestic animals and continued avoidance behavior for those that avoided on the first test. Results are taken as evidence that ECS effects are not on memory storage but on the capacity of the animal to organize information effectively and quickly in order to produce ah adaptive response.

Perspectives on Episodic-Like and Episodic Memory

“…In the one-trial contextual fear paradigm, the animal receives a food shock upon the transition from a brightly lit large chamber into a smaller dark one (Sara et al, 1975; Ebenezer, 1988; Rudy and Sutherland, 1995; Rudy et al, 2004). If the animal is reintroduced to the big chamber, e.g., after a delay of 24 h, one finds that the animal avoids the normally preferred dark chamber.…”

Retrieval and Reconsolidation: Toward a Neurobiology of Remembering

“…This was demonstrated in many studies showing recovery from ECS, hypoxia, or other experimentally induced retrograde amnesias. Effective "reminders" included a weak foot shock, exposure to the training context, or a combination of the training context and the foot shock Quartermain et al 1972;Miller and Springer 1972;Sara 1973;DeVietti and Hopfer 1974;Sara et al 1975;Gordon and Mowrer 1980). Small doses of analeptic drugs, such as strychnine, amphetamine, or piracetam, when administered before the retention test, also were shown to reverse ECS or hypoxiainduced amnesia, presumably by acting directly on retrieval processes (Sara and David-Remacle 1974;Sara and Remacle 1977).…”

Reconsolidation: A brief history, a retrieval view, and some recent issues

“…In the 1970s, a series of important contributions by Spear (1973Spear ( , 1978 argued persuasively for the importance of retrieval deficits in many cases of forgetting, and studies by R. Miller (see Miller and Springer 1972) and others (Sara 1973;Sara et al 1975) showed that ECS-induced RA for new memory could also be viewed as a problem of retrieval rather than a loss of storage. Prominent among the findings was evidence that RA could be reversed or alleviated by reminder treatments, such as exposure to the context or training apparatus or to a noncontingent footshock prior to testing, as well as the demonstration that old memories could become vulnerable to amnesic agents following reactivation.…”