neurons in the fly emerge from neuroblasts that divide in a pair wise fashion (which create the A and B daughter cell groups)
there are 34 hemilineages
all neurons within a hemilineage use the same neurotransmitter
references
Harris, R. M., Pfeiffer, B. D., Rubin, G. M., & Truman, J. W. (2015). Neuron hemilineages provide the functional ground plan for the Drosophila ventral nervous system. eLife, 4, e04493. https://doi.org/10.7554/eLife.04493