TY - JOUR
T1 - Evidence supporting the memory disruption hypothesis of electro-convulsive shock action
AU - Banker, Gary
AU - Hunt, Earl
AU - Pagano, Robert
N1 - Funding Information:
In both the passive avoidance and CER paradigms, the ECS effect is usually attributed to disruption of the memory consolidation process because of this time-dependency effect \[5\]. This hypothesis has been seriously questioned by two recent reports. Misanin, Miller and Lewis \[6\] varied the basic CER paradigm by omitting the ECS immediately after the CS-UCS presentation, then, 24 hr later, giving a second CS followed immediately by ECS. They observed an "amnesic" effect, although in the normal CER situation memory consolidation in the rat is thought to be completed within at most half an hour after the CS-UCS pairing. Using the "step down" apparatus, Schneider and Sherman \[7\]s howed that under the conditions of their experiment, animals given ECS immediately following FS did, indeed, step down rapidly the next day. The same effect was observed, however, when animals were removed from the apparatus following FS, then replaced in it and given FS followed by ECS, 6 hr after the first FS. In both the Misanin et aL and Schneider and Sherman studies, then, ECS given long after the time at which consolidation is supposed to be complete proved to have an effect on subsequent performance. Why this should be so is not clear, but in any case the results are not consistent with the usual picture of memory consolidation within seconds or minutes. We attempted to replicate the key features of the Schneider and Sherman experiment in our Experiment 1. We were unable to do so, and side observations indicated to us that previously unconsidered factors might be contaminating ~This research was supported by the U.S. Public Health Service, National Institute of Mental Health, Grant No. MH 13673-02. The support received is gratefully acknowledged. 2Gary Banker's participation was made possible by NSF Undergraduate Training Grant No. 11-5293. Present address: Department of Psychobiology, University of California, irvine, California..
PY - 1969/11
Y1 - 1969/11
N2 - Electroconvulsive shock (ECS) following training is known to disrupt performance on passive avoidance tasks. The effect is usually seen as evidence that ECS produces retrograde amnesia. Recently it was reported that if passive avoidance training was followed by a second footshock (FS) several hours after training, and then ECS, impaired avoidance was shown on subsequent testing. This was interpreted as showing that the training-ECS interval is not crucial, thus questioning the retrograde amnesia hypothesis. Our repetition of the double foot-shock studies, however, failed to replicate these observations. We did notice that the second FS made animals hyperactive, suggesting that this is not an appropriate procedure in passive avoidance studies. We then used a double foot-shock paradigm in a situation involving both passive avoidance and discriminated avoidance. The experimental animals moved more rapidly, but displayed no amnesia in their choice behavior. Amnesia was observed when ECS followed seconds after training. The results are in accord with the retrograde amnesia hypothesis.
AB - Electroconvulsive shock (ECS) following training is known to disrupt performance on passive avoidance tasks. The effect is usually seen as evidence that ECS produces retrograde amnesia. Recently it was reported that if passive avoidance training was followed by a second footshock (FS) several hours after training, and then ECS, impaired avoidance was shown on subsequent testing. This was interpreted as showing that the training-ECS interval is not crucial, thus questioning the retrograde amnesia hypothesis. Our repetition of the double foot-shock studies, however, failed to replicate these observations. We did notice that the second FS made animals hyperactive, suggesting that this is not an appropriate procedure in passive avoidance studies. We then used a double foot-shock paradigm in a situation involving both passive avoidance and discriminated avoidance. The experimental animals moved more rapidly, but displayed no amnesia in their choice behavior. Amnesia was observed when ECS followed seconds after training. The results are in accord with the retrograde amnesia hypothesis.
KW - Discrimination learning
KW - Electro-convulsive shock
KW - Memory
KW - Passive avoidance
KW - Rat
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U2 - 10.1016/0031-9384(69)90037-7
DO - 10.1016/0031-9384(69)90037-7
M3 - Article
AN - SCOPUS:50849150672
SN - 0031-9384
VL - 4
SP - 895
EP - 899
JO - Physiology and Behavior
JF - Physiology and Behavior
IS - 6
ER -