The nerves that activate a squid's jet-propelled escape mechanism have particularly big axons, allowing signals to travel at great speed.

ECONOMIST: Andrew Huxley | The

Axons are connections that carry electrical impulses, or messages, from the neurons in the brain to the rest of the body.

CNN: Intracranial hematoma

The trauma that causes intraparenchymal hematomas often is responsible for so-called white matter shear injuries torn axons in the brain's white matter.

CNN: Intracranial hematoma

In a 2012 study, students trained in a mindfulness technique had a significant decrease in stress-related cortisol and an increase in signaling connections (called axons) in a part of the brain that controls emotions.

CNN: Your detour to a stress-free life