Figure 3.

Axonal varicosities are rapidly and reversibly induced by mechanical stress in cultured CNS neurons. (A), Puffing induced rapid and reversible formation of axonal varicosities in cultured hippocampal neurons at 7 days in vitro (DIV), revealed by microscopy with transmitted lights (Gu et al., 2017). Mechanical pressure was delivered by puffing of Hank's buffer via a glass pipette onto cultured neurons with 190 mm H₂O static pressure at the tip for 150 s. Axonal varicosities slowly and partially recovered after puffing. (B), Summary of puffing-induced varicosity densities along axons from younger (7 DIV) and older (21 DIV) neurons (Gu et al., 2017). (C), TEM images of axonal segments under control condition (left) and when developing multiple varicosities induced by puffing (right) (Gu et al., 2017). Scale bars, 50 μm in (A) and 1 μm in (C).