Extracellular vesicles released by microglia and macrophages carry endocannabinoids which foster oligodendrocyte differentiation.

"Conflict of interest The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The author(s) declared that they were an editorial board member of Frontiers, at the time of submission. This had no impact on the peer review process and the final decision."

"The author(s) declare financial support was received for the research, authorship, and/or publication of this article. This work was supported by FISM under grant n° 2018/R/22 and Ricerca Finalizzata 2018 under grant n° 12365333 to CV; Fondazione Cariplo, grant n. 2015-0910 to MF. FS was supported by the research project Regione Lombardia ‘NeOn’ under grant POR-FESR 2014-2020. MG was supported by a FISM senior research fellowship n° 2016/B/2 and financed or co-financed with the ‘5 per mille’ public funding."