Figure 3.

I–V relationships in oocytes expressing mut2 receptors. (A) Voltage ramps (−130 to 30 mV membrane potential; 1.8-s duration) in the presence of either AcCho (35 μM) or strychnine (5 μM) in the same oocyte. (Inset) Sample records of strychnine currents from another oocyte tested with voltage steps (from bottom to top: −100 mV, −60 mV, −40 mV, +30 mV, inward current, downward). (B) I–V relationships performed with voltage steps showing linearity for I_AcCho and rectification at hyperpolarized potential for I_strych. AcCho concentration, 1 mM; strychnine, 500 μM.