Reactivation-dependent amnesia for appetitive memories is determined by the contingency of stimulus presentation.
Previously acquired aversive and appetitive memories are not stable and permanent. The reactivation of such memories by re-exposure to training stimuli renders them vulnerable to disruption by amnestic agents such as the noncompetitive N-methyl-D-aspartate receptor antagonist (+)-5-methyl-10,11-dihydro-SH-dibenzo{a,d}cyclohepten-5,10-imine maleate (MK-801). However, relatively little is known about the parameters that influence the reactivation process. Here, we show that the method of stimulus presentation during memory reactivation is of great importance. Male Lister Hooded rats were trained to acquire a lever press response that delivered a sucrose reward paired with a light conditioned stimulus (CS). The CS-sucrose association was then reactivated through re-exposure to the CS, either contingently upon the lever press response, or noncontingently in the absence of instrumental responding. Systemic administration of MK-801 (0.1 mg/kg) at the time of memory reactivation resulted in amnesia, and hence a reduction in subsequent sucrose seeking induced by, and dependent upon, presentation of the CS, only when the memory was reactivated contingently. Therefore, stimuli may have to be presented in the same manner at memory reactivation as during learning in order to render a previously acquired memory vulnerable to disruption. These results have important implications for the potential translational use of glutamatergic treatments in conjunction with targeted memory reactivation.
Behavioural and Clinical Neuroscience Institute, Department of Experimental Psychology, University of Cambridge, Cambridge CB2 3EB, United Kingdom. jlcl2@cam.ac.uk
Jonathan L C
JL
Lee
Barry J
BJ
Everitt
D000647:Amnesia / Q000139:chemically induced* / Q000503:physiopathology; D000818:Animals; D001070:Appetitive Behavior / Q000502:physiology*; D003216:Conditioning, Operant / Q000187:drug effects*; D003463:Cues; D016291:Dizocilpine Maleate / Q000494:pharmacology / Q000633:toxicity*; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology / Q000633:toxicity*; D008297:Male; D008568:Memory / Q000187:drug effects*; D011939:Mental Recall / Q000502:physiology*; D010775:Photic Stimulation; D051381:Rats; D016194:Receptors, N-Methyl-D-Aspartate / Q000037:antagonists & inhibitors; D013395:Sucrose
D018691:Excitatory Amino Acid Antagonists; D016194:Receptors, N-Methyl-D-Aspartate; D013395:Sucrose; D016291:Dizocilpine Maleate