Figure 6. Wire length economy and path length economy uncorrelated with either arbor length or bouton number.

(A) Wire length economy (ε) versus total axon arbor length (L_AXON) (linear regression shown as solid grey line; slope  =  −0.000272 mm⁻¹, intercept = 0.82, r² = 0.0096), (B) Wire length economy (ε) versus total boutons per arbor (slope  = −1.08e−5 mm⁻¹, intercept  = 0.85, r² = 0.1648), (C) Path length economy (γ) versus total axon arbor length (L_AXON) (slope = 0.0008 mm⁻¹, intercept  = 0.63, r² = 0.0574), and (D) Path length economy (γ) versus total boutons per arbor (slope  = 2.16e−6 mm⁻¹, intercept  = 0.66, r² = 0.0046) (n = 19). The lack of correlation implies they are scale-invariant economy measures.