Manipulating Behaviours

 Establishment of automated manipulation system to activate or inhibit specific neurons in freely moving flies

Revolutionary genetic tools have been developed to enable the identification of defined neural circuits responsible for certain behaviors. Expression of channelrhodopsin-2 (ChR2) and/or halorhodopsin (NpHR) in selected neurons can trigger or inhibit certain behaviors by optogenetic manipulation (473-nm blue laser for ChR2 activation, 593.5-nm yellow laser for NpHR inhibition) of neural activity at the millisecond time scale. Expression of temperature sensitive shibre (shits) and/or thermoTRP channels (dTrpA1 or rTTPM8) in selected neurons can trigger or inhibit certain behaviors by thermogenetic manipulation (heat-sensitive: >29°C for shits inhibition and dTrpA1 activation, cold-sensitive: <18°C for rTTPM8 activation) of neural activity. Methods to modulate activity in genetically defined cell types are essential for establishing relationships between neuronal activity and behavior. Recently optogenetic (ALTOMS) (Wu et al., 2014) and thermogenetic (FlyMAD) (Bath et al., 2014) manipulation of behavior in freely moving flies have been developed. The goal of KIM Lab. is to establish both systems described above at the University of Ottawa. This will help to connect the defined behavior to specific neural circuitry. Successful establishment of these systems include collaborations with international leaders in the field who developed each system (Dr. Ann-Shyn Chiang in Taiwan, Dr. Andrew Straw in Austria).

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 Manipulating Behaviours

FlyMAD (Fly Mind Altering Device) is a system for targeting freely walking flies (Drosophila) with lasers. This allows rapid thermo- and opto- genetic manipulation of the fly nervous system in order to study neuronal function.

Moonwalking flies are one of the extreme example how thermogenetics works. When subset of abdominal ganglion neurons are activated with UAS-trpA1 at 30℃, flies start to walk backwards! Bidaye, S. S., Machacek, C., Wu, Y., & Dickson, B. J. (2014). Neuronal control of Drosophila walking direction. Science (New York, N.Y.), 344(6179), 97–101.