Rossato Janine I, Bevilaqua Lia R M, Izquierdo Iván, Medina Jorge H, Cammarota Martín
Centro de Memória, Instituto do Cérebro, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, Brazil.
Science. 2009 Aug 21;325(5943):1017-20. doi: 10.1126/science.1172545.
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.
长期记忆（LTM）的典型特征是其持久性。然而，对于使某些长期记忆比其他记忆持续时间更长的机制，我们知之甚少。在大鼠中，当在恐惧经历后12小时而非立即或9小时将D1多巴胺受体拮抗剂SCH23390注入背侧海马体时，一种持久的恐惧长期记忆会迅速消失。相反，在相同的关键训练后时间点海马体内应用D1激动剂SK38393可将快速衰减的恐惧长期记忆转变为持久记忆。这种效应由脑源性神经营养因子介导，并受腹侧被盖区（VTA）调节。因此，长期记忆的持久性取决于VTA/海马体多巴胺能连接的激活，并且可以通过在特定的学习后时间点操纵该系统进行特异性调节。
