Posttraining glucocorticoid receptor agonist enhances memory in appetitive and aversive Pavlovian discrete-cue conditioning paradigms.
Glucocorticoid modulation of emotional memory has repeatedly been shown in aversive learning paradigms, but has received little attention in appetitive tasks. It has also been suggested that it may be selective for contextual cues. In order to investigate if glucocorticoids can modulate memory in discrete-cue conditioning of both appetitive and aversive tasks, two experiments were carried out. Male Lister-Hooded rats received pairings of an auditory cue and either food-reward (experiment 1) or footshock (experiment 2), followed immediately by posttraining injections of the glucocorticoid receptor agonist dexamethasone (0.3, 0.6, and 1.2 mg/kg) or vehicle. Dexamethasone (1.2 mg/kg) led to significantly enhanced learning. These results give support to the notion that glucocorticoids play a role in the modulation of both appetitive and aversive emotional memories and show that their role in learning goes beyond the construction of context representations. The modulation of appetitive and aversive discrete-cue learning may be subserved by a common mechanism.
Zorawski
Michael
M
Behavioural Neuroscience Laboratory, School of Psychology, Cardiff University, Tower Building, Park Place, Cardiff CF10 3YG, United Kingdom.
Killcross
Simon
S
D000818:Animals; D001070:Appetitive Behavior / Q000187:drug effects*; D001362:Avoidance Learning / Q000187:drug effects*; D003214:Conditioning, Classical / Q000187:drug effects*; D003463:Cues; D003907:Dexamethasone / Q000494:pharmacology*; D008297:Male; D008568:Memory / Q000187:drug effects*; D051381:Rats; D011965:Receptors, Glucocorticoid / Q000187:drug effects*; D013997:Time Factors
D011965:Receptors, Glucocorticoid; D003907:Dexamethasone