Genes and Dynamics of Memory Systems Group, Neurobiology Unit, CNRS, ESPCI, 10 Rue Vauquelin, 75005 Paris, France.
Curr Biol. 2011 Oct 11;21(19):1647-53. doi: 10.1016/j.cub.2011.08.032. Epub 2011 Sep 29.
It is broadly accepted that long-term memory (LTM) is formed sequentially after learning and short-term memory (STM) formation, but the nature of the relationship between early and late memory traces remains heavily debated [1-5]. To shed light on this issue, we used an olfactory appetitive conditioning in Drosophila, wherein starved flies learned to associate an odor with the presence of sugar [6]. We took advantage of the fact that both STM and LTM are generated after a unique conditioning cycle [7, 8] to demonstrate that appetitive LTM is able to form independently of STM. More specifically, we show that (1) STM retrieval involves output from γ neurons of the mushroom body (MB), i.e., the olfactory memory center [9, 10], whereas LTM retrieval involves output from αβ MB neurons; (2) STM information is not transferred from γ neurons to αβ neurons for LTM formation; and (3) the adenylyl cyclase RUT, which is thought to operate as a coincidence detector between the olfactory stimulus and the sugar stimulus [11-14], is required independently in γ neurons to form appetitive STM and in αβ neurons to form LTM. Taken together, these results demonstrate that appetitive short- and long-term memories are formed and processed in parallel.
人们普遍认为，长期记忆（LTM）是在学习和短期记忆（STM）形成后顺序形成的，但早期和晚期记忆痕迹之间的关系的性质仍然存在很大争议[1-5]。为了阐明这个问题，我们在果蝇中使用了嗅觉奖赏条件作用，其中饥饿的果蝇学会将气味与糖的存在联系起来[6]。我们利用 STM 和 LTM 都是在一个独特的条件作用周期后产生的这一事实[7,8]，证明了奖赏性 LTM 能够独立于 STM 形成。更具体地说，我们表明：（1）STM 的检索涉及蘑菇体（MB）γ神经元的输出，即嗅觉记忆中心[9,10]，而 LTM 的检索涉及αβ MB 神经元的输出；（2）STM 信息不会从γ神经元转移到αβ神经元以形成 LTM；（3）腺苷酸环化酶 RUT 被认为是嗅觉刺激和糖刺激之间的巧合检测器[11-14]，它在γ神经元中独立形成奖赏性 STM，在αβ神经元中形成 LTM。综上所述，这些结果表明，奖赏性短期记忆和长期记忆是平行形成和处理的。
