2010年2月19日的《细胞》杂志刊载了清华大学钟毅教授在短期记忆遗忘机理研究方面取得的重大进展。刚刚获取的记忆通常会很快遗忘，该论文认为这样的快速遗忘其实是一种主动的行为，用以抹掉旧的记忆腾出空间来存储新的记忆，在果蝇中，小G蛋白Rac对主动遗忘具有调控作用。通过分子遗传方法操纵Rac的活性即可改变果蝇遗忘的速度，Rac活性低时，遗忘变慢，活性高时，遗忘加速。

钟毅教授这篇题为“果蝇遗忘受小G蛋白Rac调控”("Forgetting Is Regulated through Rac Activity in Drosophila")的论文极大地挑战了人们把遗忘当成一个被动、负面过程的传统看法。这个遗忘机制与记忆机制是平行的，两者相互独立，遗忘并不影响记忆的获得。Rac蛋白独立的诱发遗忘过程。这些研究结果表明，Rac在遗忘过程中扮演重要的角色，它介导遗忘产生，与此同时不影响记忆的获得过程。

推荐原始出处：

Cell, Volume 140, Issue 4, 579-589, 19 February 2010 DOI:10.1016/j.cell.2009.12.044

Forgetting Is Regulated through Rac Activity in Drosophila

Yichun Shuai, Binyan Lu, Ying Hu, Lianzhang Wang, Kan Sun, Yi Zhong

Department of Biological Sciences and Biotechnology, Tsinghua University, Beijing 100084, P.R. China
Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA

Initially acquired memory dissipates rapidly if not consolidated. Such memory decay is thought to result either from the inherently labile nature of newly acquired memories or from interference by subsequently attained information. Here we report that a small G protein Rac-dependent forgetting mechanism contributes to both passive memory decay and interference-induced forgetting in Drosophila. Inhibition of Rac activity leads to slower decay of early memory, extending it from a few hours to more than one day, and to blockade of interference-induced forgetting. Conversely, elevated Rac activity in mushroom body neurons accelerates memory decay. This forgetting mechanism does not affect memory acquisition and is independent of Rutabaga adenylyl cyclase-mediated memory formation mechanisms. Endogenous Rac activation is evoked on different time scales during gradual memory loss in passive decay and during acute memory removal in reversal learning. We suggest that Rac's role in actin cytoskeleton remodeling may contribute to memory erasure.