The vesicular monoamine transporter ( VMAT ) is a transport protein integrated into the membrane of synaptic vesicles of presynaptic neurons . The Vesicular Monoamine Transporter ( VMAT ) is a transport protein that is integrated into the membrane of synaptic vesicles of presynaptic neurons . The presynaptic monoamine transporter ( VMAT ) is a transport protein integrated in the membrane of the synaptic vesicles of vesicular neurons .