英语听力文摘 English Digest 593、神经细胞丧失会怎么样？

搜索关注在线英语听力室公众号：tingroom，领取免费英语资料大礼包。

 

　　When you were born, almost all of the one trillion neurons, or nerve¹ cells, in your brain had already formed. But those neurons still had a lot of growing to do.

 

　　As kids grow, neurons in the brain branch out and make new connections. You could even say that the life a neuron is all about connections. If neurons don’t form appropriate connections with each other and other structures in the brain, they’ll eventually die.

 

　　Luckily, we’re born with far more neurons than we need, and some neuron loss is a normal part of brain development.

 

　　Around age 20, we begin to lose neurons to the process of aging. By 75, nearly one-tenth of the neurons you were born with have died. That may sound frightening, but it doesn’t mean you lose ten percent of your intelligence. Here’s why.

 

　　Most neurons can’t divide to form new cells, so there’s no way to replace them if they die. But living neurons continue to grow all of our lives, forming new branches and connections with other neurons. That makes up for much of what we’ve lost. And there’s another type of brain cell, called a glial cell, that can divide to form new cells. Glial cells help neurons do their job better and provide a framework² to support them.

 

　　But brain power isn’t just about numbers of cells. Eating a well-balanced diet and experiencing and learning³ new things all influence the way neurons branch and connect. In other words, the more you use your brain, the better it works⁴.

 

 

 

 

　　神经细胞丧失会怎么样？

 

　　从你出生的那一刻起，几乎所有的在你大脑中的一万亿个神经元（神经细胞）就已经形成。但是这些神经细胞仍会持续不断地生长。

 

　　伴随着孩子长大，大脑中的神经元会产生分支并且建立新的连接。甚至可以说神经细胞的一生都是围绕着连接展开的。如果相互的神经元或者神经元与大脑中的其它结构没有产生适当的连接，那么它们最终都会死亡。

 

　　幸运的是，我们生来就有着远超过我们所需要的神经细胞，所以在大脑发育过程中损失部分神经细胞是正常的。

 

　　在20岁左右，我们开始失去神经元，步入变老的过程。在75岁时，几乎十分之一的你与生俱来的神经细胞已经死亡。这可能听起来怪吓人的，但是这并不意味着你失去了百分之十的智力。让我们来看看这是为什么。

 

　　大多数的神经细胞不能靠分裂而产生新的细胞，所以一旦神经细胞死亡就没有其它细胞可以替代。但是存活的神经细胞则继续伴随着我们的整个生命过程不断成长， 形成新的分支并且与其他神经细胞建立连接。这就弥补了大部分我们已经失去的神经细胞。并且，还有另一种类型的脑细胞，叫做神经胶质细胞，这种细胞可以靠分 裂来产生新的细胞。神经胶质细胞帮助神经元更好的完成它们的工作并且提供可以支持他们的框架。

 

　　但是脑力不仅仅取决于神经细胞的数量。饮食均衡，体验和学习新的事物都能影响神经元分叉和连接的方式。换句话说，大脑用得越多越灵活。

分享到：