Serotonin (IMAGE) Rockefeller University Press Caption This schematic drawing of a serotonergic neuron shows exocytotic release of serotonin from vesicles (red arrow) and the nonexocytotic release described by Mlinar and colleagues (blue arrow). Reuptake of serotonin (green arrow) is blocked by SSRI antidepressants, increasing the extracellular serotonin concentration. Credit Adell 2015 Usage Restrictions Reporters may freely use these materials in news coverage, with the appropriate credit information. License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.