Enhancing a declarative memory in humans: The effect of clonazepam

M.L.C. RODRÍGUEZ A, J. CAMPOS B, C. FORCATO A, R. LEIGUARDA B, H. MALDONADO A,1, V.A. MOLINA C, M.E. PEDREIRA

NEUROPHARMACOLOGY

PERGAMON-ELSEVIER SCIENCE LTD

Lugar: New York; Año: 2013 vol. 64 p. 432 - 442

0028-3908

A consolidated memory recalled by a specific reminder can become unstable (labile) and susceptible tofacilitation or impairment for a discrete period of time. This labilization phase is followed by a process ofstabilization called reconsolidation. The phenomenon has been shown in diverse types of memory, anddifferent pharmacological agents have been used to disclose its presence. Several studies have revealedthe relevance of the GABAergic system to this process. Consequently, our hypothesis is that the system isinvolved in the reconsolidation of declarative memory in humans. Thus, using our verbal learning task,we analyzed the effect of benzodiazepines on the re-stabilization of the declarative memory. On Day 1,volunteers learned an association between five cue- response-syllables. On Day 2, the verbal memorywas labilized by a reminder presentation, and then a placebo capsule or 0.25 mg or 0.03 mg of clonazepamwas administered to the subjects. The verbal memory was evaluated on Day 3. The volunteerswho had received the 0.25 mg clonazepam along with the specific reminder on Day 2, exhibited memoryimprovement. In contrast, there was no effect when the drug was given without retrieval, when thememory was simply retrieved instead of being reactivated or when short-term memory testing wasperformed 4 h after reactivation. We discuss the GABAergic role in reconsolidation, which showsa collateral effect on other memories when the treatment is aimed at treating anxiety disorders. Furtherstudies might elucidate the role of GABA in the reconsolidation process associated with dissimilarscenarios.