Grouping tendencies of MNs based on steady-state voltage- and current transfers (open and closed triangles). ‘High’, ‘Medium’, and ‘Low’ levels of synaptic background activities on dendrites were modeled by 5000, 20000 and 50000 Ωcm2 specific dendritic membrane resistivities respectively. To reveal grouping tendencies cluster analysis was used with the Pair group and Ward’s methods (see horizontal labels starting with ‘pg’ and ‘wm’) with differently weighted (‘fact1’ and ‘fact2’) descriptors. The five descriptors were the 10th, 25th, 50th, 75th, and 90th percentiles of standardized and area weighted distributions of voltage and current transfers between dendritic points and the soma. The two sets of weighting factors of percentiles (‘fact1’ and ‘fact2’) were as follows: In factor set 1, the 10th and 90th percentiles were weighted by 0.2 and the 25th and 75th percentiles by 0.8. In factor set 2, the weighting factors were 0.33 for the 10th and 90th percentiles and 0.67 for the 25th and 75th percentiles. In both sets of weighting factors the weight was 1 for the 50th percentile. In cluster analyses the Euclidian distances were used. Homogeneity indexes, last order clustering index (A) and Peterson’s index (B), were used to measure segmental homogeneities of MNs within last order clusters, which reflect segregation of cervical and lumbar MNs between the clusters. Homogeneity indexes with values closer to one indicate higher similarity (poorer segregation) of cervical and lumbar MNs. Continuous horizontal lines mark the levels of homogeneity indexes below which segmental separation of MNs by their voltage and current transfer properties is significant.