Textbooks may have misdrawn this basic brain structure for 100 years

Researchers at Johns Hopkins Medicine using cryo-electron microscopy found that axons of mouse neurons have repeating nanoscale swellings called 'unlinked varicosities.' This challenges the classic view of axons as smooth tubes and points to a role for membrane forces in signal transmission.

• Axons appear as chains of small beads, not smooth tubes
• Swellings are not linked to synapses and are not a sign of damage
• Higher sugar concentration and membrane tension reduced bead size
• Cholesterol removal changed structure and slowed electrical signal