VMAT functions in loading the neurotransmitters dopamine, serotonin, histamine, norepinephrine, and epinephrine into transport vesicles. Collectively these neurotransmitters are referred to as monoamines. VMAT uses the same transport mechanism for all types of monoamines. VMATs transport monoamines from the cytosol into high-concentration storage vesicles. Transport vesicles are released into the space between neurons, called the synaptic cleft, where they convey a chemical message to the next neuron. VMATs also function in sorting, storing, and releasing neurotransmitters, and are believed to participate in protecting these neurotransmitters from autoxidation. VMATs are also known to continue biochemical modification after loading of certain neurotransmitters.