第3165期:Part-human part-mouse brain developed in science breakthrough

While mice with partly-human brains might sound a Kafkaesque experiment, the scientists say that these are not mice that think like humans, rather they're animals that are altered so that some of their brain tissue is human. 虽然拥有部分人类脑组织的小鼠听起来像是一场 “卡夫卡式” 的实验，但科学家表示，这些小鼠并不会像人类一样思考。更准确地说，它们只是经过改造的动物，其部分脑组织来源于人类。

The researchers engineered mice to develop almost none of their own cerebralcortex, that's the outer layer that's sometimes referred to as grey matter. It handles higher-level thinking, memory and senses. They then used skin cells taken from humans, reprogrammed them and grew them into pieces of brain-like tissue called organoids – collections of connected living brain cells. When these organoids were implanted into the mice, they formed connections with the rest of the brain and the spinal cord, functioning like brain tissue. 通过基因工程手段，研究人员让这些小鼠几乎不发育自身的大脑皮层。大脑皮层就是大脑的外层，有时也被称为 “灰质”，负责高级思维活动、记忆和感觉处理。随后，研究人员用取自人类的皮肤细胞，将其重新编程，培育成名为 “类器官” 的类脑组织。类器官由相互连接的活体脑细胞组成。这些类器官被植入小鼠后，与大脑的其它区域和脊髓建立了连接，并发挥与脑组织相似的功能。

Having working human brain cells inside a living animal, the scientists say, gives them a new way to understand the biological causes and develop treatments for brain disorders, including dementia, epilepsy and cerebral palsy. The study raises questions about what it means to change the brain of an animal and exactly how theselaboratorymice will experience the world. So, there'll be ongoing discussions weighing the scientific value of these mice against these ethical challenges. 科学家表示，在活体动物的大脑中植入能正常发挥功能的人类脑细胞，为他们理解脑部疾病的生物学成因、开发新疗法提供了新途径，这些疾病包括痴呆、癫痫和脑瘫。该研究也引发了一些质疑，例如改变动物的大脑意味着什么，以及这些实验小鼠究竟会如何感知和体验世界。因此，如何权衡这些小鼠的科学价值与伴随而来的伦理挑战，相关讨论还将持续下去。