Converting an allocentric goal into an egocentric steering signal. (https://pubmed.ncbi.nlm.nih.gov/38326612/)

These scientists wanted to understand how insects like flies know where they are going. They studied the brains of flies to see how their brain cells work together to help them navigate.

They found that there are certain brain cells called EPG neurons that tell the fly which direction it is facing at any given moment. But sometimes, the direction the fly wants to go in is different from the direction it is actually facing.

The scientists also discovered another group of brain cells called FC2 neurons that tell the fly which direction it wants to go in. When these cells are activated using a special light, the flies start walking in the direction the scientists want them to go.

The EPG and FC2 neurons are connected to a third group of brain cells called PFL3 cells. These cells are very interesting because they respond to both the direction the fly is facing and the direction it wants to go in. They help the fly figure out how to turn and move in the right direction.

Using all this information, the scientists made a model that explains how the brain compares the two directions - the one the fly is facing and the one it wants to go in - to create a signal that tells the fly which way to move. They tested this model and found that it works.

Finally, they did an experiment where they disrupted the communication between the PFL3 cells and found that the flies had trouble going in the right direction. This confirmed that the PFL3 cells are really important for the flies to navigate correctly.

So, these scientists discovered how the fly's brain compares two different directions to help it know which way to go. This is really important because it helps us understand how animals can find their way around and go where they want to go.

Mussells Pires P., Zhang L., Parache V., Abbott LF., Maimon G. Converting an allocentric goal into an egocentric steering signal. Nature. 2024 Feb 7. doi: 10.1038/s41586-023-07006-3.