Pharmacological profile of ACh, NIC, ACE and CLO on rat 34 nAChRs expressed in Xenopus oocytes. (A) ACh (n = 12) and NIC (n = 7) elicit robust currents, while ACE (n = 8) and CLO (n = 7) induce much more modest currents. Due to the solubility limit in DMSO, ACE and CLO could not be used at concentrations upper than 2 × 10 M. (B) Concentration–response curves of ligand-evoked currents which are expressed as a % of ACh–elicited current amplitude. Two Y axis were used to visualize ACh and NIC (left), and CLO and ACE (right). Inset: Hexamethonium (HEX, 0.2 μM) an 3-containing nAChRs antagonist, inhibits ACh-elicited current as expected. (C) Peak currents (±SEM) elicited by 20 μM ACh, NIC, ACE or CLO on rat 34 nAChRs. Different lowercase letters above the graphs indicate significant differences between treatments according to Tukey’s multiple comparison post hoc test (p < 0.05).