Figure 4.

Developmental regulation of spine motility. (a) A histogram of the percent motility at two developmental stages in Purkinje cells. Note how motility is reduced from 73.1 ± 11.8% at P10 + 2 div (n = 14) to 45 ± 14.9% at P22 + 2 div (n = 7); Mann–Whitney U test; P < 0.001). Developmental changes in motility in (b) acute and cultured cortical or (c) cultured hippocampal neurons. Age is computed as the sum of postnatal age and days in vitro (cultured slices were made at P0–1). The line represents the best fit to data from cultured cortical neurons (regression ANOVA F < 0.0006).