Wiping Out Bad Memories

A hot topic in neuroscience is memory. Not only increasing it, but erasing it...of the sort that Jim Carrey fools with in the movie, Eternal Sunshine of the Spotless Mind.

Last week researchers from the University of Toronto published a paper in Science that shows successful obliteration of a fearful memory in mice. This study is significant in that they focused on a specific set of nerve cells that were associated with a very specific memory.

Researchers trained mice to fear a tone, by matching that tone with an electric shock to their feet. So when the tone rang, the mice froze in fear.

Then they flipped a genetically engineered-switch that wiped out a set of neurons, called the CREB-making neurons. CREB is a protein that spikes in the lateral amygdala, when we experience a scary event.

Now, when the tone rang, the mice kept on with their mouse-like activities. No other memories, nor their ability to form new memories, were affected. The effect was specific, potent and long-lasting.

We need to note we are not anywhere close to erasing memory in humans. And really, we need to think hard about which memories to squash, if we ever could. After all, memory is how we learn.

Like that time last winter when I thought it was a fun idea to test walking on thin ice. Think I want to remember that one.

消除糟糕的记忆

记忆是神经科学的一个很热门的话题，就像电影《美丽心灵的永恒阳光》（Eternal Sunshine of the Spotless Mind）里的Jim Carrey一样，人们尝试消除记忆，而不仅仅是增强我们的记忆力。

上周来自多伦多大学（University of Toronto）的研究人员们在《科学》（Science）杂志上发表的一篇文章显示，他们成功地把老鼠的一种可怕的记忆消除掉了。该项研究的重大意义在于为研究人员们集中研究了与某种特定记忆相关的特定的一组神经细胞。
 
研究人员们通过对老鼠加以训练，使它们对某一声音感到恐惧。使用的方法是，研究人员在老鼠听到这种声音的时候，就对老鼠的脚施加电击。所以，一旦这种声音响起来，这些老鼠就会吓得不能动弹。

然后，研究人员们通过基因改变技术消除了一组名为“生成CREB”的神经细胞。CREB是一种蛋白质，当我们经历令人害怕的事情的时候，外侧杏仁核中CREB的含量会升高。

现在，当这种声音响起的时候，这些老鼠仍然继续自己的活动。这些老鼠的其它记忆以及它们形成新记忆的能力都没有受到影响。这种改变的效果具有特定性、长期性而且强大。

我们需要注意的是，我们还远远不能消除人的记忆。实际上，如果我们能消除记忆，我们需要认真想想哪些记忆需要消除。毕竟我们是通过记忆来学习的。

比如，去年冬天的时候我认为在薄冰上行走以检测冰的厚度是个有趣的想法。现在我觉得我还是想珍藏这个记忆。

Vocabulary:

Neuroscience: 神经科学
Obliteration: 记忆的根除
Neuron: 神经细胞
Spike: 升高
Lateral: 边缘的
Amygdala: 杏仁核
Potent: 强大的
Scary: 害怕的
Squash: 压碎；挤压

知识点滴：

spike作为名词是“长钉”的意思。但是它作为动词的时候的一个常用意思是“迅速升高、提高”。比如利息的陡然升高， “Interest rates spiked up last week”（上周利息陡然升高）。