Expression of mouse serotonin transporter RNA in Xenopus laevis oocytes

The serotonin transporter removes serotonin from the synapse, terminating the action of this neurotransmitter. We have taken an initial step towards cloning the serotonin transporter by obtaining its expression in Xenopus oocytes. We found that mouse brainstem is a suitable source of serotonin transporter mRNA and that synthesis of the transporter in injected oocytes occurs steadily over a 3 day period. Uptake of [3H] serotonin was inhibited by 18 nM citalopram, a specific inhibitor of serotonin transport.