|Science. 2009 Aug 21;325(5943):1017-20. |
Dopamine controls persistence of long-term memory storage.
Rossato JI, Bevilaqua LR, Izquierdo I, Medina JH, Cammarota M.
Centro de Memória, Instituto do Cérebro, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, Brazil.
The paradigmatic feature of long-term memory (LTM) is its persistence. However, little is known about the mechanisms that make some LTMs last longer than others. In rats, a long-lasting fear LTM vanished rapidly when the D1 dopamine receptor antagonist SCH23390 was injected into the dorsal hippocampus 12 hours, but not immediately or 9 hours, after the fearful experience. Conversely, intrahippocampal application of the D1 agonist SK38393 at the same critical post-training time converted a rapidly decaying fear LTM into a persistent one. This effect was mediated by brain-derived neurotrophic factor and regulated by the ventral tegmental area (VTA). Thus, the persistence of LTM depends on activation of VTA/hippocampus dopaminergic connections and can be specifically modulated by manipulating this system at definite post-learning time points.