Inside the Head of a Locust

What am I looking at?

This is a composite image of neurons in the brain of a locust (each side is a mirror image of the other). You can see two very distinct neurons in orange (1) and blue (2) that have been filled with fluorescent dye. You can also see groups of other neurons that have been exposed to the fluorescent dye externally but not filled with it (3).  

Biology in the background

Locusts use their olfactory system to find food, find a mate, organize group behaviors like swarming, and much more. To find food, they can “smell” specific chemical compounds emitted by the plants they eat. To find mates and organize group behaviors, they detect chemical compounds emitted by other locusts. These chemicals are detected by odorant receptors on their antennae and mouthparts; the receptors are present on specific neurons that then pass the information on to neurons in the olfactory center of the locust’s brain. Locusts rely heavily on their olfactory system to experience the world around them and to direct many of their behaviors.

A locust’s brain is about 4 millimeters across, or roughly six times smaller than a human thumbnail.

Technique  

This image was created using confocal microscopy.