Figure 5.

Spine motility is regulated by actin polymerization but is not affected by blocking or inducing activity. Superimposed outlines of spines (labeled 1–6 for Purkinje and 7–16 for cortical pyramidal neurons) from time-lapse sequences before a and after b application of Cytochalasin D. Motility indexes of the spines demonstrate that Cytochalasin D (c) reduces spine motility (Mann–Whitney U test, P = 0.003). (d)Lack of effect of choline on the motility indexes of Purkinje cells (spines 1–10) and cortical pyramidal neuron (spines 11–15). (e) Lack of effect of blocking AMPA receptors on motility (Purkinje cell). (f) Lack of effect of stimulating neuronal activity with potentiation medium (hippocampal pyramidal neuron). P > 0.5 for d–f.