Comparison of dendrite morphology in transgene-expressing motor neurons as a function of branch order: primary dendrites emanate directly from the cell body; branching within a primary dendrite produces secondary dendrites and so on.Filled bars represent GluR1(Q)flip-expressing cells,shaded bars represent GluR1(R)flip-expressing cells, and unfilled barsrepresent LacZ controls. A, Number of dendrites of each order. Repeated measures ANOVA demonstrates significant differences in the number of dendritic segments (F(14,490) = 7.739;p < 0.001), with a greater number of segments found in GluR1(Q)flip-expressing neurons compared with other groups (Scheffé's post hoc test). B, Average length of each branch. Repeated measures ANOVA revealed significant group differences in the average size of each dendritic segment (F(2,70) = 3.291;p = 0.043), with segments of GluR1(Q)flip-expressing cells displaying shorter segment sizes than GluR(R)flip-expressing neurons or LacZ controls.Asterisks represent individual radial bins in which variance within groups was measured.