Spontaneous recovery after a stroke accounts for a significant part of the neurological recovery in patients. However limited, the spontaneous recovery is mechanistically driven by axonal restorative processes for which several molecular cues have been previously described. We report the acceleration of spontaneous recovery in a preclinical model of ischemia/reperfusion in rats via a single intracerebroventricular administration of extracellular vesicles released from primary cortical astrocytes. We used magnetic resonance imaging and confocal and multiphoton microscopy to correlate the structural remodeling of the corpus callosum and striatocortical circuits with neurological performance during 21 days. We also evaluated the functionality of the corpus callosum by repetitive recordings of compound action potentials to show that the recovery facilitated by astrocytic extracellular vesicles was both anatomical and functional. Our data provide compelling evidence that astrocytes can hasten the basal recovery that naturally occurs post-stroke through the release of cellular mediators contained in extracellular vesicles.

中风后的自发恢复占患者神经功能恢复的重要部分。无论多么有限，自发恢复都是由轴突恢复过程机械驱动的，之前已经描述了几个分子线索。我们报告了在大鼠缺血/再灌注的临床前模型中，通过单次脑室内施用从原代皮质星形胶质细胞释放的细胞外囊泡，自发恢复加速。我们使用磁共振成像、共聚焦和多光子显微镜将胼胝体和纹状体皮质回路的结构重塑与 21 天内的神经功能联系起来。我们还通过重复记录复合动作电位来评估胼胝体的功能，以表明星形细胞外囊泡促进的恢复既具有解剖学意义又具有功能意义。我们的数据提供了令人信服的证据，表明星形胶质细胞可以通过释放细胞外囊泡中包含的细胞介质来加速中风后自然发生的基础恢复。