PLC speeds and PH probes slow M current suppression. (A and B) Normalized mean M current at −20 mV from six cells expressing either transfected PLCβ₁-YFP (open circles, A) or low levels of PH(PLCδ₁)-CFP and PH(PLCδ₁)-YFP (open circles, B). For comparison, control M current from five cells lacking exogenous PLC or PH probes (black circles). Note the different time scales for onset and washout.