Activity bump
The patch of active compass neurons. Where it sits on the ring shows which way the fly is facing.
See it in a lesson
Related terms
- Turn neurons
- Nerve cells that fire when the fly turns and push the bump around the compass. Scientists call them P-EN2 neurons.
- Compass neurons
- A ring of nerve cells that keeps track of which way the fly is facing. Scientists call them E-PG neurons.
- Ring neurons
- Nerve cells that bring what the fly sees, such as landmarks, to the compass. They quiet the compass neurons, and that holds the bump in place.
- Landmark
- Something the fly sees that stays in place, like the sun or a tree. The fly uses it to keep its sense of direction steady.
- Protocerebral bridge
- A bar-shaped part of the fly’s brain, the protocerebral bridge. The compass neurons and the turn neurons both run through it.