Characterizing the neurons in the fruit fly courtship song circuit

As part of a complex courtship behavior, male flies vibrate their wings to produce a distinctive song that conveys a message to nearby females. Using internal information and cues from females and the environment, males decide moment to moment whether to sing and how.
Although scientists now know a lot about how fly movements produce songs, it was still not clear which cells and circuits in the fly’s nervous system enable the behavior.
Now, using a suite of novel tools Janelia researchers have pinpointed the group of neurons in the nerve cord - a structure analogous to our spinal cord - that produce and pattern the fly’s two major courtship songs.
This video shows of some of the different genetically engineered flies used to characterize the song circuit. The left image shows light microscopy images from different fly strains expressing different neurons. The right image shows the same neurons identified by electron microscopy in the connectome of the male adult nerve cord. The middle image shows an overlay of the anatomy imaged by light microscopy and electron microscopy.
Credit: Joshua Lillvis / HHMI Janelia Research Campus