Synaptosomal Serotonin Uptake and Its Selective Inhibitors SSRI

2 Synaptosomal Serotonin Uptake and Its Selective Inhibitors (SSRI) 

Serotonin (5-hydroxytryptamine, 5-HT) occurs in the intestinal wall, where it regulates motility and secretion in blood platelets, where it modulates platelet aggregation and vascular blood flow and in the CNS, where it acts as a neurotransmitter in areas of the midbrain. At least seven different receptors for serotonin have been characterized, which mediate a wide variety of different physiological effects. Depression and anxiety are thought to be the result of actions on 5-HTia receptors in the brain limbic system. Following release from neurons by a depolarizing action potential at central synapses, the activity of 5-HT is terminated by neuronal reuptake. This is performed by a synaptic membrane amine transporter protein, specific for 5-HT, which also co-transports sodium and chloride ions to repolarize the neuronal membrane. 

SSRls and sertraline in particular, represented a significant advance over the frequent adverse effects of the earlier drug classes [3]. Further progress in this held has been achieved with dual- and triple-uptake inhibitors, which inhibit the uptake of serotonin, dopamine and adrenaline, three neurotransmitters that are most closely linked to depression [4]. 

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