Figure 3. Unstructured positioning of insertion points. A, D, Same dendritic segments as in Figure 2, along with points of insertion of spines (white dots). Red dots represent the white boxed areas from Figure 2, with potential spine helixes. B, E, Insertion points of dendritic spines of dendritic segments from A and D. C, F, Unfolded arrangement of the insertion points in B, E, after straightening (a) and unrolling (b). Artificial helical patterns, containing the same number of points as in the real dendrite, were created for comparison in each example (c). d, The corresponding unrolling process for the helical samples. G, H, Monte Carlo envelope tests of these examples. Graphs represent allowed random band (shaded), the theoretic distribution function GCSR(r) (red dotted line), and the estimated Ĝ(r) obtained from the patterns analyzed (black line) using the proposed edge correction. Because examples did not surpass the shaded envelope, the null hypothesis of complete spatial randomness (CSR) was not rejected.