When you were born, almost all of the one trillion neurons, or nerve cells, in your brain had already formed.
当你出生时，大脑中的一万亿个神经元（神经细胞）几乎已经全部形成。
But those neurons still had a lot of growing to do.
但是这些神经细胞仍然会不断生长。
As kids grow, neurons in the brain branch out and make new connections.
随着孩子成长，大脑中的神经元会不断发育并建立新的连接。
You could even say that the life a neuron is all about connections.
甚至可以说神经细胞一生都在不断地建立连接。
If neurons don't form appropriate connections with each other and other structures in the brain, they'll eventually die.
如果神经元不再与大脑中的其他神经元或其它结构建立适当的连接，那么它们最终会死亡。
Luckily, we're born with far more neurons than we need, and some neuron loss is a normal part of brain development.
所幸，人类生来携带的神经细胞远远超过所需，所以大脑在发育过程中损失部分神经细胞是正常的。
Around age 20, we begin to lose neurons to the process of aging.
在20岁左右，神经元会逐渐消失，机体开始走向衰老。
By 75, nearly one-tenth of the neurons you were born with have died.
人到75岁时，几乎一成的神经细胞已经死亡。
That may sound frightening, but it doesn't mean you lose ten percent of your intelligence. Here's why.
这听起来很吓人，但是并不意味着你失去了百分之十的智力。接下来揭晓原因。
译文为秀哈英语翻译，未经授权请勿转载!
