The fruit fly brain is small—picture a grain of sand—but still exceedingly complex, consisting of lots of cells organized into complex circuits. This image shows the two lobes of the brain of a fruit fly larva with hundreds of neurons, colored green, and stem cells, colored magenta. Stem cells actively divide to produce the neurons and more stem cells. The cell bodies of the neurons from each stem cell form discrete clusters and send out long, delicate processes, called axons, that connect them to other cells, forming the netlike structure in the lower part of the image. 

Credits: Image courtesy of Omer Bayraktar, PhD, in the laboratory of HHMI investigator Chris Doe, PhD, University of Oregon

Technical Notes: The image was obtained using laser scanning confocal microscopy, a technique used to examine relatively thick tissue samples.

Links:

http://uoneuro.uoregon.edu/doelab/

http://uanews.org/story/the-strikingly-similar-brains-of-flies-and-men

http://www.hhmi.org/news/enigmatic-neurons-help-flies-get-oriented