HTR5A and major depressive disorder: In this study, an attempt has been made using neurochemical methods to verify the mode of action of RSP, a competitive antagonist of VMAT-2, compared to the transporter’s non-competitive antagonists, TBZ and VBZ, on the cytoplasmic (resting) and axonal stimulation-evoked vesicular release of NA and 5-HT from ex vivo slice preparations dissected from mouse hippocampus, which is involved in memory and learning processes, as well as in depression.