Optimal tapering follows quadratic decay. (A) Normalized optimal diameters (black dots) in cable pieces of different lengths divided into 10 segments each. In all cases a quadratic equation (red lines) could well describe the course of tapering. The fixed diameter of the first segment corresponding to the axon piece is not shown. (B) Changing the size of the leak (length of the first segment) did not alter the relative course of tapering.