Spine neck repair of group C and group D spines. A, Incomplete spine mesh from group C. The orange dot indicates the base point, between the spine neck and the dendritic shaft. B, Repair of the neck by adding a cylinder between the base point and the closest vertex of the head. This cylinder is not the real neck; it was added just to enable measuring the neck length and separating the head and neck. C, Separation into head (green) and neck (blue). D, Incomplete spine mesh, consisting of two components (group D). E, Repair of the neck by adding a cylinder between the two components, resulted in a connected spine. F, Separation into head (green) and neck (blue). Scale bar: 200 nm. Extended Data Figure 4-1 shows the comparison between the morphologic parameters of only the complete spines (group A) and the complete and repaired spines (groups A, C, and D).