Figure 3.

Enhanced Ca²⁺-permeability of heteromeric 5-HT₃/α4 receptors expressed in oocytes. Ion currents mediated by homomeric 5-HT₃Rs (Left) and heteromeric 5-HT₃/α4 receptors (Right) were evoked at holding potentials of −60, −20, and +20 mV (bottom to top traces) with 10 μM 5-HT under control, Ca²⁺-free, and Cl⁻-free conditions (see Materials and Methods). Traces recorded under Ca²⁺-free conditions were obtained from the same oocytes used to record control traces. (Insets) Magnified current traces recorded at the holding potential of −20 mV.