Basically what we need to do is replace cells in those few areas of the brain that lose cells at a respectable rate, especially neurons, but we don't want to replace them any faster than that -- or not much faster anyway, because replacing them too fast would degrade cognitive function.
基本上我们需要做的是取代大脑 的几个领域的细胞的流失率， 尤其是神经元，但我们不想比 那流失率更快地取代任何细胞 – 因为更换地太快会降低认知功能。