excessive [ɪkˈsesɪv]
adj. 过分的；过多的
One key to a longer life could be a quieter brain without too much neural activity, according to a new study that examined postmortem brain tissue from extremely long-lived people for clues about what made them different from people who died in their 60s and 70s.
一项新研究表明，长寿的一个关键因素可能是大脑比较平静，且没有太多的神经活动。该研究剖检了寿命极长之人死后的脑组织，以寻找他们与六七十岁即去世之人的不同之处。
“Use it or lose it” has dominated thinking on how to protect the aging brain, and extensive research shows there are many benefits to remaining physically and mentally active as people get older.
关于如何保护衰老的大脑，“用进废退”一直主宰着人们的想法。大量研究表明，随着年龄的增长，保持身体和精神上的活跃有很多好处。
But the study, published in the journal Nature, suggests more isn’t always better. Excessive activity – at least at the level of brain cells – could be harmful.
但发表在《自然》杂志上的这项研究表明，并不总是越多越好。至少过度的脑细胞活动可能是有害的。
“The completely shocking and puzzling thing about this new paper is … [brain activity] is what you think of as keeping you cognitively normal. There’s the idea that you want to keep your brain active in later life,” said Michael McConnell, a neuroscientist at the Lieber Institute for Brain Development, who was not involved in the study.
“这篇新论文最让人震惊和困惑的是……（大脑活动）就是你所认为的能让你保持正常认知的事物。而你希望在日后的生活中保持大脑活跃，”利伯尔大脑发育研究所神经学家迈克尔·麦康奈尔说道，他并没有参与这项研究。
“The thing that is super unexpected is … limiting neural activity is a good thing in healthy aging. It’s very counterintuitive.”
“非常令人意外的是……有限的神经活动有利于健康地衰老，但它却是违反常理的。”
Researchers at Harvard Medical School analyzed brain tissue donated to human brain banks by people ranging in age from their 60s and 70s to centenarians who lived to be 100 or older.
哈佛大学医学院的研究人员分析了60多岁、70多岁到100多岁的老人捐献给人类大脑库的脑组织。
They found people who died before their mid-80s had lower levels in their brains of a protein called REST that tamps down genes involved in sparking brain activity, compared to the very oldest people. REST had already been shown to be protective against Alzheimer’s disease.
他们发现，与特别长寿的人相比，那些85岁之前就去世的人，他们大脑中名为REST的蛋白质含量较低，这种蛋白质能抑制激发大脑活动的基因，而REST已被证明可以预防老年痴呆症。
今日词汇
excessive [ɪkˈsesɪv]
adj. 过分的；过多的
the excessive, covetous love of money
对金钱过度的、贪婪的追求
The excessive consumption of sugar leads to problems of obesity.
摄入过多糖分会导致肥胖问题。
