Efficient encoding of motion is mediated by gap junctions in the fly visual system
Fig 2
GJs reduce the variability and enhance the clustering of the combined axonal responses to different axes of rotation.
(A) Response of VS5 to stimuli embedded with natural scenes as a function of the rotation axis when GJs are absent from the VS network. The continuous line shows the mean voltage response; the pink shaded area represents one standard deviation from that mean. (B) As in A but when the VS cells are all connected with GJs = 1 μS (see the circuit in Fig 1C). (C) Joint axonal voltage response of VS5 versus VS6 in the absence of GJs. A total of 1000 samples for both θ = 0° (green) and for θ = 60° (red) in response to natural stimuli are shown (see Materials and Methods). Their 95% confidence ellipses are shown in black. (D) As in C but with GJs = 1 μS. (E) Joint axonal voltages for VS5-6-7 of the left compound eye without GJs and (F) with GJs = 1 μS for six different axes of rotation (indicated by respective colors). Note the greatly improved separability of the axes of rotation in the presence of GJs.