We study behavioral roles of biogenic amine neurotransmitters in the fruit fly, Drosophila melanogaster. These transmitters, including the well studied molecules dopamine and serotonin, have roles in the fly that parallel those found in higher animals, validating use of this important genetic model. We study these roles with pharmacological, physiological and genetic approaches. Drugs such as aerosolized free base cocaine directly

target this system, and can be used as probes to study its state in vivo. Studies using cocaine as a probe identified an intriguing connection with circadian genes, a connection under intensive study. These transmitters also have roles in circadian rhythmicity, and in setting motor activity levels and light sensitivity of motor activation and circadian entrainment. We have developed assays to study the effects of dim light that have identified specific roles for these transmitters. Tools under development will allow these roles to be localized to small neuronal subsets, and ultimately, the brain circuitry responsible for behavioral outputs.

Link to videos showing cocaine-induced fly behaviors>>

S. (Cole) Hardie, J. Hirsh, (2006) An Improved Method For The Separation And Detection Of Biogenic Amines In Adult Drosophila Brain Extracts By High Performance Liquid Chromatography. J. Neurosci Methods, 153, 243-9.

S. Hardie, J. X. Zhang, J. Hirsh, (2007). Trace Amines Differentially Regulate Adult Locomotor Activity, Cocaine Sensitivity, and Female Fertility in Drosophila melanogaster, Dev. Neurobiol. 1;67(10):1396-1405 Published Online: 28 Mar 2007.

A. Claridge-Chang, R. D. Roorda, E. Vrontou, L. Sjulson, H. Li, J. Hirsh & G. Miesenböck, (2009). Writing Memories with Light Addressable Reinforcement Circuitry. Cell, 139(2):405-15.

J. Hirsh, T. Riemensperger, H. Coulom, M. Iché, J. Coupar, S. Birman, (2010). Roles of Dopamine in Circadian Rhythmicity and Extreme Light Sensitivity of Circadian Entrainment. Curr Biol, 20, 1–6.