Figure 2.

Long-distance suppression of bursting activity in Ipc. A, Top trace, Extracellular recording of bursting activity in Ipc evoked by moving a 2° spot at 45°/s for 1 s (signal trace 1), inside the receptive field. Bottom trace, Same recording location as above but with a second spot of the same size and velocity but 100° higher in the visual field, which began to move when the first stimulus was halfway through its course (signal trace 2). This suppressed the bursting responses from the first spot. Suppressed bursting activity is replaced by high-frequency firing of lower amplitude (arrows). B, Superposition of five traces (stimuli as in A) illustrates the robustness of the phenomenon.