Dopamine in the dorsal hippocampus negatively modulates the persistence of cocaine-related memories

KRAMAR, CECILIA P; BARBANO, M. FLAVIA; MEDINA, JORGE H

Congreso; XXVI Reunion Anual de la Sociedad Argentina de Investgacion en Neurocienciasi; 2013

One of the hallmarks of drug addiction is its persistence over time. Drug use and abuse depends on associations between environmental stimuli and drug effects. Although much effort has been done to elucidate the mechanisms involved in establishing drug-associated memories, how they persist over time remains unknown. Combining pharmacological and biochemical tools with behavioral assays, we manipulate the persistence of cocaine-conditioned place preference (CPP) memory. A weak CPP training resulted in an increased release of dopamine (DA) in the dorsal hippocampus late after training. Blocking hippocampal D1-like receptors (D1R) around the same time period promotes the duration of a short-lasting cocaine-associated memory. Conversely, the maintenance of long-lasting cocaine CPP memory was selectively abolished by intrahippocampal infusions of D1R agonist SKF 38393 or of a specific agonist of the D1R coupled to phospholipase C cascade, indicating that dopamine inputs to the hippocampus negatively controls the persistence of cocaine-associated memory storage.