Brain derived exosomes (BDEs) are extracellular nanovesicles that are collectively released by all cell lineages of the central nervous system and contain cargo from their original cells. They are emerging as key mediators of communication and waste management among neurons, glial cells and connective tissue during both physiological and pathological conditions in the brain. We review the rapidly growing frontier of BDEs biology in recent years including the involvement of exosomes in neuronal development, maintenance and communication through their multiple signaling functions. Particularly, we highlight the important role of exosomes in Alzheimer’s disease (AD), both as a pathogenic agent and as a disease biomarker. Our understanding of such unique nanovesicles may offer not only answers about the (patho) physiological course in AD and associated neurodegenerative diseases but also ideal methods to develop these vesicles as vehicles for drug delivery or as tools to monitor brain diseases in a non-invasive manner because crossing the blood brain barrier is an inherent capability of exosomes. BDEs have potential as biomarkers and as therapeutic tools for AD and related brain disorders in the near future.

脑源性外泌体（BDE）是细胞外纳米囊泡，由中枢神经系统的所有细胞谱系共同释放，并含有来自其原始细胞的物质。它们正在成为大脑生理和病理条件下神经元、神经胶质细胞和结缔组织之间沟通和废物管理的关键介质。我们回顾了近年来 BDE 生物学快速发展的前沿领域，包括外泌体通过其多种信号传导功能参与神经元发育、维持和通讯。特别是，我们强调了外泌体在阿尔茨海默病（AD）中的重要作用，既作为病原体又作为疾病生物标志物。我们对这种独特纳米囊泡的理解不仅可以提供有关 AD 和相关神经退行性疾病的（病理）生理过程的答案，还可以提供开发这些囊泡作为药物输送载体或作为以非侵入性方式监测脑部疾病的工具的理想方法因为穿越血脑屏障是外泌体的固有能力。在不久的将来，BDE 有潜力作为 AD 和相关脑部疾病的生物标志物和治疗工具。