Heart-rate reactivity to reminder treatment predicts test performance in rats given ECS following training

Abstract

Two experiments compared the capacity of reminder treatments to modify retention performance in rats either strongly trained and given ECS or weakly trained and given no ECS. Heart rate was monitored during the reminder sessions. In Experiment 1, the factorial combinations of stimulation of the mesencephalic reticular formation (MRF) (present, absent) followed by the presentation of the cue originally paired with foots hock in training, a tone (present, absent), were evaluated as reminder stimuli. Results indicated that both groups showed decreased heart rate to the presentation of the tone in the reminder session. However, in the retention test, ECS animals given tone reminder showed increased retention, whereas weakly trained animals showed decreased retention. Experiment 2 used a shorter interval to onset of the tone in the reminder session. Heart rate to the reminder tone again decreased in weakly trained animals, but no change was obtained in ECS animals. No change in test performance as a result of reminder was noted in either group. These results support the notion that ECS following training influences memory retrieval systems and suggest that heartrate reactivity may be used to predict the behavioral effects of reminder treatment in ECS animals.Reminder treatments interpolated between training and a retention test quite consistently increase retention performance in animals given an amnesic treatment following training. In most instances, this reminder effect is not obtained in, for example, animals trained but not given amnesic treatment or animals not trained (e.g., DeVietti & Hopfer, 1974). However, controversy exists as to the meaning of this effect. Some regard the reminder literature as suggesting that amnesic treatments affect memory retrieval processes (e.g.,

Latent inhibition measured by heart rate suppression in rats

“…Given the absence of a significant interaction between prior exposure treatment and baseline heart rate activity, the raw data were transformed to suppression ratios (DeVietti & Porter, 1969;Wittman & DeVietti, 1981) for subsequent analyses. This transfonnation compares heart rate activity during CS presentation with heart rate activity occurring prior to stimulus introduction (baseline measure).…”

Rethinking Memory Impairments: Retrieval Failure

“…However, there are numerous examples of memory recovery following post-training amnesic treatments and the range of conditions is similar to the cue-dependent amnesia domain (see Table 1). Since the 1960s, research has shown that after post-training amnesia, the original conditioned response can spontaneously recover over time (e.g., Cooper & Koppenaal, 1964; also see, Parsons & Davis, 2011;Quartermain, McEwen, & Azmitia, 1970Squire & Barondes, 1972;Zinkin & Miller, 1967) or when the original US (i.e., reinstatement; e.g., Misanin, Miller, & Lewis, 1968; also see, Devietti & Hopfer, 1974;Land, Bunsey, & Riccio, 2000;Miller, Ott, Berk, & Springer, 1974;Miller & Springer, 1972;Quartermain, McEwen, & Azmitia, 1970;Radyushkin & Anokhin, 1999) or CS are presented again before testing (Dekeyne, Deweer, & Sara, 1987;Deweer, Sara, & Hars, 1980;Deweer & Sara, 1981;Gordon & Mowrer, 1980;Wittman & DeVietti, 1980). Further support for that view comes from studies demonstrating that recovery from post-training amnesia can be induced by the amnesic treatment itself (i.e., state-dependency learning; Hinderliter, Webster, & Riccio, 1975;Mactutus, McCutcheon, & Riccio, 1980;Mactutus & Riccio, 1978;Overton, 1964Overton, , 1972Thompson & Neely, 1970;Vardaris, Gaebelein, & Riccio, 1973), including protein synthesis inhibitors (e.g., Bradley & Galal, 1988).…”