Fig. 7.

Formation of long tunneling nanotubes between brain ECs to transfer Exis. Exos can be transferred to adjacent ECs via the formation of long, hollow tubes (A; Scale bar: 1000 nm). Magnification of target area B. Tunneling nanotubes with sticky ends attach to juxtaposed cell surfaces (Scale bar: 200 nm). M1: propose membrane of cells with originating tunneling nanotubes; M2: target cell membrane interacted with tunneling nanotubes from other cells. PC: paracellular space between juxtaposed brain ECs. Blue circles: tunneling nanotube formation; Purple arrow indicates several pores on the membrane of tunneling nanotubes. Yellow arrows indicate the interaction between tunneling nanotubes and target BCs at the extremities. Reprinted with permission [167], Copyright 2021. Frontiers in Neuroanatomy