The dopamine response in mouse neuroblastoma cells is mediated by serotonin 5HT3 receptors

Serotonin (5HT) and dopamine (DA) induce, in neuroblastoma N1E-115 cells, a transient membrane depolarization associated with an inward current. The half-maximum response is obtained with 2 microM 5HT or 200 microM DA. The maximum response to 5HT is 2-3 times that to DA. The selective 5HT3 receptor antagonists ICS 205-930 and MDL 72222 at nanomolar concentrations block both the 5HT- and the DA-induced response. High concentrations (10 microM) of 5HT2 receptor antagonists are without effect. It is concluded that, in N1E-115 cells, 5HT and DA activate a single population of 5HT3 receptors.