Visualizing Retinotopic Half-Wave Rectified Input to the Motion Detection Circuitry of Drosophila.

Dierk Frithjof Reiff (1) , Johannes Plett (1) , Marco Mank (1) , Oliver Griesbeck (1) , Alexander A Borst (1)

1 Department of Systems and Computational Neurobiology

In the visual system of Drosophila, photoreceptors R1-6 relay achromatic brightness information to five parallel pathways. Two of them, the lamina monopolar cells L1 and L2, represent the major input lines to the motion detection circuitry. Here we devised a new method for the optical recording of visually evoked changes in intracellular Ca2+ in neurons, using targeted expression of a genetically encoded Ca2+ indicator. Ca2+ in single terminals of L2 neurons in the medulla carries no information about the direction of motion. However, the observed strong increase in intracellular Ca2+ induced by light-OFF and only small changes induced by light-ON suggest half-wave rectification of the input signal. Thus, L2 predominantly transmits brightness decrements to downstream circuits that then compute the direction of image motion.

Mots clés: Sensory Systems; Neuroimaging; Neurophysiology; Neuroscience; Physiology

Dierk Frithjof Reiff, Johannes Plett, Marco Mank, Oliver Griesbeck, Alexander A Borst. Visualizing Retinotopic Half-Wave Rectified Input to the Motion Detection Circuitry of Drosophila.. Nature Neuroscience, 2010, ⟨10.1038/nn.2595⟩. ⟨hal-00554657⟩