Fig. 3.

Effects of membrane depolarization on agonist-induced increases in CREB phosphorylation in SH-SY5Y cells. The effect of increasing extracellular [K⁺] (from 4.7 to 44.7 mM) per se, or in combination with MCh (1 μM) or bradykinin (300 nM) addition on phospho-CREB immunoreactivity was assessed in confluent SH-SY5Y cell monolayers. Representative immunoblots for phospho-CREB and total CREB are shown beneath the histogram (Ctr, buffer only addition; M, MCh (1 μM); B, bradykinin (300 nM); K⁺, +40 mM K⁺; M/K⁺ and B/K⁺, K⁺-depolarization in presence of respective agonist). Histogram data are shown as means ± S.E.M. for at least 3 independent experiments.