Aberrant accumulation of serotonin in dopaminergic neurons

作者：Mossner R^*; Simantov R; Marx A; Lesch KP; Seif I

来源：Neuroscience Letters, 2006, 401(1-2): 49-54.

DOI：10.1016/j.neulet.2006.02.081

• serotonin
• dopamine
• transporter
• monoamine oxidase A

Gene targeting approaches greatly facilitate insight into the functioning of monoamine transporters, the targets of potent antidepressants. The serotonin transporter (5-HTT) is the molecular target of a large number of antidepressants. To assess the clearance of serotonin (5-HT) in the absence of the 5-HTT, we have generated double knockout mice lacking both the 5-HTT and the catabolizing enzyme monoamine oxidase A (MAOA). We found aberrant 5-HT accumulation in the striatum of these MAOA/5-HTT double knockout mice. By additional ablation of the dopamine transporter (DAT), this aberrant 5-HT accumulation was abolished in MAOA/5-HTT/DAT triple knockout mice. Thus, aberrant uptake of 5-HT occurs in dopaminergic terminals under conditions of elevated 5-HT levels, and this aberrant uptake is mediated by the DAT. These findings have important consequences for antidepressant therapy, since during treatment of depression with selective serotonin reuptake inhibitors, clearance of 5-HT by dopaminergic neurons may reduce the desired therapeutic elevation of extracellular 5-HT levels. This provides a molecular rationale for improving antidepressant efficacy by additional pharmacological inhibition of the DAT.

• 出版日期2006-6-19