Blue-Green Zebrafish Brain

What am I looking at?

This is a coronal section (sliced from top to bottom) through the middle of an adult zebrafish brain. The neurons’ nuclei (indicating the location of the neuronal cell bodies) are blue (1). The actin (a protein that’s present throughout neurons) is green (2). The grayish-white spaces between the colored sections are fluid-filled ventricles that provide nutrients to the cells of the brain (3).

Biology in the background

The brains of all animals are made of cells called neurons and glia. Neurons are the “lead actors” within the brain, carrying out most of the organ’s major functions. Glia are the “supporting actors,” aiding the neurons in carrying out their functions and keeping neurons healthy.

Neurons need to communicate with one another to perform complex tasks. They do this by sending signals over long distances along the paths that their axons and dendrites established during development. The brain is generally organized so that the cell bodies of neurons responsible for certain tasks are grouped together in specific areas. This image shows the areas where the cell bodies are concentrated (in blue) and the areas where their projections are concentrated (in green), giving us a view of how the zebrafish brain is organized.

The brain of a zebrafish is about 2.5 millimeters across, or roughly 10 times smaller than a human thumbnail.

Technique

This image was created using confocal microscopy.