Terminates the action of serotonin by its high affinity sodium-dependent reuptake into presynaptic terminals. Expression is specific to cell bodies in the ventral ganglion of the embryonic and larval nervous system. This protein is the target of psychomotor stimulants such as amphetamines or cocaine. Belongs to the sodium:neurotransmitter symporter (SNF) (TC 2.A.22) family.