Fig. 2.
Neonatal exposure to isoflurane or wild-type PDZ2 peptide decreases hippocampal mushroom spine density in mice. (A) Representative images showing dendritic segments and spines; s = stubby, m = mushroom, t = thin; scale bar, 2.5 µm. (B) Schematics showing dendrite branches and spine types sampled. (C) Density of spines among exposed groups assessed at 7 weeks. Mice in cohort 1 were exposed to oxygen (control, 100% O2) or isoflurane (1.5% ISO in 98.5% O2) and cohort 2 were injected with PDZ2MUT (8 mg/kg inactive mutant peptide) or PDZ2WT (8 mg/kg active wild-type peptide). Control (n = 16), Isoflurane (n = 11), PDZ2MUT (n = 14), and PDZ2WT (n = 16). n = number of animals. (C, left) Mushroom: control versus isoflurane, P < 0.0001; PDZ2MUT versus PDZ2WT, P < 0.001. (C, middle) Thin: control versus isoflurane, P = 0.184 and PDZ2MUT versus PDZ2WT, P < 0.001. (C, right) Stubby: control versus isoflurane, P = 0.257 and PDZ2MUT versus PDZ2WT, P = 0.452. Data were analyzed with 1-way ANOVA followed by Holm-Sidak’s tests. *P < 0.050, **P < 0.010, ***P < 0.001, ****P < 0.0001.