Fig. S2.

Missing Mi15 cell in the Home column. (A) Synaptic connections between Mi15 and C3/Mi4. Mi15 is normally presynaptic to both C3 and Mi4 in its own column. However, because the Home column lacks Mi15, the Home C3 and Home Mi4 are instead postsynaptic to Mi15s in the neighboring columns (the number of their contacts is shown in parentheses). (B) Cell in column E (green) is a typical Mi15 with two main branches (arrows). The Mi15 in column B (magenta) extends a branch in the Home column (arrowheads), where the normal Mi15 is missing. This branch connects to Mi4, which is normally postsynaptic to the Mi15 in its own column. (C) Plan view of B. Dotted circles indicate approximate boundaries of columns.