Fig. 5

Hippocampal neurons isolated from VPA animals showed resistance to glutamate-induced synapse remodeling in vitro. Hippocampal neurons in culture isolated from control and VPA animals were exposed to glutamate (5 µM, 3 min) and immunostained (DIV14) for a MAP-2 and b SYN (×4 magnification insets show SYN puncta pattern). c Quantification of MAP-2 dendritic area revealed that neurons for both experimental groups remodeled their dendritic tree after glutamate exposure. d SYN puncta number quantification depicted a reduction in neurons from control animals in response to glutamate exposure which was absent in neurons from VPA animals. e Neurons from control animals showed an increase in individual SYN puncta area when exposed to glutamate, while neurons from VPA animals showed a preserved puncta size. f In accordance with puncta number reduction, total SYN puncta area decreased in the control group. g, i Pre-treatment with MK-801 prevented dendritic tree retraction in neurons from both control and VPA animals. h, j Pre-treatment with MK-801 prevented glutamate induced SYN puncta reduction in control neurons and showed no effect in neurons from VPA animals. Results are expressed as mean values (± SD, control n = 45 neurons, VPA n = 45 neurons, except for: g–j glutamate plus CNQX n = 30 neurons, i, j MK-801 n = 25 neurons, from 3 independent cultures). c–f ns: non-significant; *p < 0.05; **p < 0.01 between groups by two-way ANOVA followed by Tukey test; ns: non-significant; ^#p < 0.05 between groups by Kruskal Wallis test; g–j: ns: non-significant; *p < 0.05; **p < 0.01 between groups by one-way ANOVA followed by Tukey test. Scale bar: 50 µm