No abstract

Rats showed retrogarde amnesia when electroconvulsive shock was administered 24 h after a fear conditioning trial when the shoek was preceded by some of the specific conditioning cues but not others. This result replicates the findings of Misanin, Miller, & Lewis (1968) and suggests that ECS can act to produce retrograde amnesia by means other than disrupting memory consolidation. Retrograde amnesia produced by electroconvulsive shock after reactivationof a consolidated memory trace: A replication* The finding that retrograde arnnesia (RA) r e s u l t s from an ECS administered shortly after a training trial is well documented (e.g., King, 1965; Young & Day, 1970), and this result has most often been interpreted as due to an action of ECS on memory storage proeesses (Glickman, 1961; McGaugh, 1966; McGaugh & Dawson, 1 9 7 1). T hat me m 0 r y s tor a ge disruption is a singular memory effect of ECS was recently brought into question by Misanin, Miller, & Lewis (1968), who reported that ECS administered 24 h after fear conditioning, when preceded by a brief "reminder" of that conditioning, resulted in an amnesia that was as complete as that produced when ECS immediately followed the fear c o nd i t i o n i n g trial. This finding suggests that ECS may modify memory processes other than memory storage. However, the impact of this re port was tempered by the failure of Dawson & McGaugh (1969) to replicate this effect. The present study attempted to replicate the general finding of Misanin et al that RA can be produced by pairing specific conditioning cues with ECS the day following fear conditioning. SUBJECTS AND APP ARATUS The Ss were 95 male Long-Evans rats from the Central Washington State Psychology Department animal colony and ranged between 90 and 120 days of age at the beginning of the experiment. They were individually housed, maintained on Purina Lab Chow ad lib, and allowed only 15 min of water a day in the home eage for the duration of the experiment. Drink training, fear conditioning, *This research was conducted in accord with the AP A statement of "Guiding principles for the humane care and use of anim als," December 15. 1962. tRequests for reprrnts should be sent to Terry L. DeVietti. Department of Ps v c hologv , Central Washington State College. Etlensb urg, Wash. 98926.