生物谷报道：MIT Picower学习和记忆中心(Picower Institute for Learning and Memory)研究人员最近找到一种控制外伤事件造成恐惧记忆的分子机制。研究结果刊登于7月15日在线版《Nature Neuroscience》杂志。
Picower神经学教授Li-Huei Tsai与其同事发现，抑制一种名为Cdk5的激酶，有利于消除特定环境造成的恐惧记忆。相反，如果海马区（大脑的记忆存储中心）中这种酶的活性上升，所产生的恐惧会持续下去。脑发育过程早期，Cdk5作用于p35蛋白，帮相新生脑细胞形成并迁移到正确位点。在近期工作中，MIT研究人员观察Cdk5影响大脑建立或消除恐惧相关记忆的能力。"很明显，抑制Cdk5有助于消除小鼠的恐惧记忆。这些数据指出了一个治疗情感障碍（emotional disorders）的有效途径，为经历创伤后应激障碍或恐怖症折磨的患者带来福音。"Tsai说。
情感障碍如创伤后应激障碍和恐惧症，来自于大脑无力停止对与特殊事件或者连续事件有关的恐慌。对某些人来说，创伤事故的恼人记忆不会自动消失，甚至会越来越严重，最终影响他们的正常生活。
此次，研究人员首先将遗传工程小鼠在特定环境中，进行足底电击，然后再将小鼠放入相同环境中，不加足底电击。结果，体内Cdk5活性上升的小鼠很难清除对电击的恐惧记忆，继续颤抖。相反，Cdk5活性被抑制的小鼠，电击恶梦在其发现第二个环境中不存在电击时便消失。
"我们用小鼠证明，恐惧记忆的消失依赖于消除蛋白激酶Cdk5相关分子途径中的成分，"Tsai说 "我们发现Cdk5通过影响其它关键激酶的活性而抑制消失，至少部分抑制。"
原文出处：
A hippocampal Cdk5 pathway regulates extinction of contextual fear
Farahnaz Sananbenesi, Andre Fischer, Xinyu Wang, Christina Schrick, Rachael Neve, Jelena Radulovic & Li-Huei Tsai
Published online: 15 July 2007 | doi:10.1038/nn1943
Abstract | Full text | PDF (414K) | Supplementary Information
相关基因：
CDK5
Official Symbol CDK5 and Name: cyclin-dependent kinase 5 [Homo sapiens]
Other Aliases: PSSALRE
Other Designations: protein kinase CDK5 splicing
Chromosome: 7; Location: 7q36
Annotation: Chromosome 7, NC_000007.12 (150381832..150385929, complement)
MIM: 123831
GeneID: 1020
作者简介：
Li-Huei Tsai, Ph.D.
Dr. Tsai is also Picower Professor of Neuroscience in the Department of Brain and Cognitive Sciences at the Massachusetts Institute of Technology. She received her Ph.D. degree from the University of Texas Southwestern Medical Center at Dallas under the direction of Bradford Ozanne. She then joined Ed Harlow's laboratory at Cold Spring Harbor Laboratory and Massachusetts General Hospital for postdoctoral training. Prior to her move to MIT, Dr. Tsai was Professor of Pathology at Harvard Medical School.
RESEARCH ABSTRACT SUMMARY:
Li-Huei Tsai is interested in the mechanisms that underlie the production and positioning of neurons during brain development, signaling at synapses, and the demise of the nervous system in adult life.
View Research Abstract
