经过几十年的研究，科学家们对大脑和脊髓内专门细胞的功能有了局部的了解。通过研究大脑的发育，他们能够识别出在不同神经元群体中活跃的基因，以及这些神经元在大脑中的位置。在某些情况下，这些基因随后可用于在基因层面上敲除神经元，让我们得以初步了解它们的功能，这建立在我们从大脑受损区域研究中获得的信息基础之上。
Over decades of research, scientists have built up a partial picture of what specialized cells within the brain and spinal cord do. By studying how the brain develops, they could identify genes that were active in different populations of neurons and where in the brain those neurons resided. In some cases, these genes could then be used to genetically delete the neurons, allowing us to get some indication of what they might be doing, building on the information we've obtained from studies of brains with damaged regions.
但这种方法有其局限性。大脑具有足够的灵活性，可能会适应某些细胞的丢失，并且这些细胞在发育早期的丢失可能会改变它们通常会与之形成连接的任何神经元的发育。如果在保持大脑完好的情况下激活和关闭神经元，将会提供多得多的信息。
But this approach has its limits. The brain is flexible enough to potentially adapt to the loss of some cells, and their loss early in development may alter the development of any neurons they would have normally formed connections with. It would be far more informative to activate and shut down the neurons in an otherwise intact brain.
今天的诺贝尔生理学或医学奖授予了三位科学家——卡尔·代瑟罗斯（Karl Deisseroth）、彼得·黑格曼（Peter Hegemann）和格奥尔格·纳格尔（Georg Nagel），他们发展了我们精确做到这一点的能力。从对趋光单细胞藻类的研究开始，这些研究人员以及许多其他人建立了一个全新的研究领域，我们现在称之为光遗传学：利用光来改变由单个基因活动标记的神经细胞的行为。
Today's Nobel Prize in Physiology or Medicine rewards three people—Karl Deisseroth, Peter Hegemann and Georg Nagel—who developed our ability to do precisely that. Starting from studies of single-celled algae that are attracted to light, these and many other researchers built an entire field of study that we now call optogenetics: using light to alter the behavior of nerve cells marked by the activity of individual genes.