The Journal of Neuroscience, July 26, 2006, ():
Robust Integration of Motion Information in the Fly Visual System Revealed by Single Cell Photoablation
J. Neurosci. Kalb et al.
26: 7898
Supplemental data
Files in this Data Supplement:
- supplemental material
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Suppl. Figure 1. A, Sample trace of the membrane potential to a motion stimulus before (upper trace) and after ablation (bottom trace). Before ablation the VS-cell responds with a graded depolarisation and superimposed spikelets to motion in its preferred direction. Following ablation, the motion response is completely abolished. The black bar indicates the duration of the motion stimulus. B, Left: Raw fluorescence image of another VS-cell showing part of its dendritic tree with the recording electrode and part of the axon. The cell was iontophoretically filled with the phototoxic dye carboxyfluorescein. Right: Image of the same region after ablation with intense laser light. The profile of the cell has become invisible and background intensity has increased, which is probably due to the consequence of the fluorescence dye leaking from the damaged cell.
- supplemental material
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Suppl. Figure 2. Sensitivity of V1’s input synapses to Co2+. A, Scheme of experimental setup: Extracellular recording of V1 spikes was performed during visual stimulation before and after pressure application of CoCl2-solution to V1’s input region. For pressure application of Co2+ a glass electrode with large tip opening was filled with 100 mM CoCl2 and connected to a syringe. The electrode was inserted into the brain at the approximate location of VS-V1 synapses. Pressure to the syringe was applied by hand and not systematically controlled. B, Raster plots of V1’s spiking activity during motion in the preferred direction before application of Co2+ (upper trace) and afterwards (bottom traces). C, Quantification of Co2+ effect on V1’s motion induced responses (open squares) and baseline activity (asterisks). Each symbol was calculated from a single response trace. Co2+ application led to a marked decrease in the motion-induced response and a slight decrease of baseline activity of the V1-neuron. These effects suggests that transfer of motion signals between VS and V1 is at least partly mediated by chemical synaptic transmission, since Co2+ is known to disrupt transmission at chemical synapses by blocking presynaptic Ca2+ channels.
