Calcium Imaging in Drosophila During Walking and Flight Behavior

Abstract

Drosophila melanogaster is a genetic model organism with many experimental advantages, including the ability to genetically manipulate specific sub-populations of neurons. The combination of physiology and genetic tools is increasingly being applied to questions in systems neuroscience [1]. Our goal is to understand circuit computations underlying sensory-motor transformation in the fly brain. This requires recording not just neural activity but also the fly's behavior. Towards this end, we have developed a novel experimental setup [2] for two-photon calcium imaging while the fly is walking on an air-supported ‘Buchner’ ball [3, 4] in a virtual arena [5]. These recordings represent the first examples of functional imaging in behaving Drosophila and provide a platform for future explorations of decision-making and sensory-motor transformations in this powerful genetic model organism. We have also adapted the setup for calcium imaging in tethered flying Drosophila. In complementary work, a different group has succeeded in whole-cell patch-clamp recording from fruit flies during flight behavior [6]. Motion-sensitive interneurons in the visual system of walking and flying Drosophila show modulation of their responses depending on their behavioral state [6, 7]. Under natural conditions the visual input of the fly changes and is controlled by the movement of the fly. Closed-loop tethered behavior allows approaching this situation in a controlled experimental setting. We demonstrated the feasibility of closed loop flight behavior during calcium imaging and compare neuronal responses during open and closed-loop flight behavior. 1. Olsen and Wilson (Trends Neurosci., 2008) 2. Seelig, Chiappe, Lott, Dutta, Osborne, Reiser, Jayaraman (Nat Meth, 2010) 3. Gotz and Wenking (J Comp Physiol, 1973) 4. Bohm, Schildberger and Huber (JEB, 1991) 5. Reiser and Dickinson (J Neurosci Meth, 2008) 6. Maimon, Straw, Dickinson (Nat Neurosci, 2010) 7. Chiappe, Seelig, Reiser, Jayaraman, (Curr Biol, 2010)