Effects of a G-CSF deficit on maximal dendritic length (A) and branching (B) of hippocampal CA1 pyramidal neurons. Values reflect means (±SEM) of four neurons from each of five mice belonging to each experimental group (n = 20 neurons). G-CSF deficiency led to a significant reduction in the length of apical dendrites accompanied by significantly reduced amounts of branch points (p < 0.05, Student's t test), whereas the dendritic length and amount of nodes of the basal dendrites remained unaffected. C, Tracings of representative neurons traced in the CA1 region and dentate gyrus from G-CSF-deficient (left) or wild-type (right) mice. Note the decrease in branching and reduction of the apical dendrite in G-CSF-deficient neurons. Scale bar, 20 μm. G-CSF deficiency resulted also in a significant decrease of dendritic length of hippocampal dentate gyrus neurons (mean G-CSF^−/−, 548.57 μm ± 140.04 SEM; mean wild type, 1543.57 ± 272.85; p < 0.05, Student's t test).