Figure 3: Histological analyses of peripheral nervous system phenotype. Standard hematoxylin-eosin staining (HE) and immunohistochemical (IHC) staining were performed on all peripheral nervous system tissue sections. (a) Representative HE and IHC staining of peripheral nerves taken from a Dhh-Cre; ; Cnp-EGFR ( Pten/C-EGFR) experimental and Dhh-Cre; ; Cnp-EGFR (Pten-het/C-EGFR) control mice using antibodies against the proliferative marker (Ki67), Schwann cell/oligodendrocyte lineage marker (S100ß), activated Ras/Mapk/Erk signaling by phospho-Erk1/2 (pErk), activated Pi3k/Akt signaling by phospho-Akt (pAkt) detection, and activated mTor signaling by phospho-S6 (pS6). Negative controls, sections incubated without the primary antibody gave no significant signal above background (data not shown). (b) Semiquantitative analysis of proliferative peripheral nerve cells in various control and experimental cohorts. Representative peripheral nerves were isolated from each cohort and IHC stained using the Ki67 proliferative marker. The number of Ki67-positive peripheral nerve cells was counted and shown as a percentage of total cells per counted field of view at 20x magnification (mean ± standard deviation). Peripheral nerves were taken from Pten/C-EGFR experimental mice, Dhh-Cre; ( Pten) and Pten-het/C-EGFR control mice. No Ki67-positive cells were detected in sciatic nerves isolated from FVB/N mice (Supplementary Figure 1). n, number of mice from each cohort; N.S.: nonsignificance between indicated cohorts; P: unpaired t-test.