SLC6A3 and schizophrenia: This paradigm may also be useful for identifying the environmental factors associated with schizophrenia given that social defeat results in deficits in prepulse inhibition [3], an enhanced mesocorticolimbic dopamine response [4, 5], increased phasic activity in ventral tegmental area (VTA) dopaminergic neurons [6], reductions in striatal dopamine transporter (DAT) binding [7], and behavioral and neuronal cross-sensitization to amphetamine [8].