Figure 7.

CF boutons systematically overlap with molecular layer interneuron somata. A, Number of overlaps of terminal (hatched) and en passant boutons onto interneuron somata per CF by branch type. B, Representative CF superimposed with both its actual boutons and an equal number of boutons randomly shuffled within the CF bounding box (large rectangular dotted border). Actual boutons that do and do not contact interneurons are colored maroon and gold, respectively. Shuffled boutons that do and do not contact interneurons are colored dark and light green, respectively. Example regions (smaller solid and dashed squares) are enlarged upper right above the figure to appreciate detail. CF and bouton radii are thickened 1.5× for clearer visualization. C, Interneuron overlap ratio between actual and shuffled boutons. Potential contacts between CF boutons and interneuron somata occur significantly more than by chance (horizontal dashed unity line). D, Further distinction by branch type. Only distal en passant boutons do not overlap with interneurons significantly beyond chance. Error bars indicate 95% confidence intervals.