Figure 3. Boutons existed for weeks showed higher stability than those newly formed.
(A) Axonal boutons formed within the previous week and pre-existing boutons were identified. The survival rates of pre-existing and newly formed spines were measured over the next 2–3 weeks. Boutons pre-existed for more than one-week showed a significantly higher survival rate than those formed during the previous week (P < 0.05). (B) Boutons existed for at least one month showed a significantly higher survival rate during the next five months than those formed over the previous month. Data are presented as mean ± S.E.M. * P < 0.05.