Figure 2

Axon regeneration inhibitors enhance ERK activity. (A-C) Cerebellar neurons were incubated with CSPGs (A), Nogo (B) or myelin (C) for indicated time-points followed by Western Blotting for total and activated ERK (P-ERK). All three axon regeneration inhibitors activated ERK with shorter incubation periods being more effective. Bar diagrams depict P-ERK levels normalized to total ERK levels for individual experiments. (D,E) Cerebellar neurons were stimulated with Nogo (D) or myelin (E) for 1 h. Cultures were pre-incubated with pharmacological inhibitors for 15 mins. Interference with Rho-GTPase (ToxB) and more pronounced MAP kinase (PD98059) signaling, but not cAMP/PKA signaling (Rp-cAMPS), blocked Nogo (D) or myelin’s (E) potential to fully activate ERK. Numbers in bars indicate independent cell cultures analyzed.