HYPERLOCOMOTION AND INDIFFERENCE TO COCAINE AND AMPHETAMINE IN MICE LACKING THE DOPAMINE TRANSPORTER

Disruption of the mouse dopamine transporter gene results in spontaneo us hyperlocomotion despite major adaptive changes, such as decreases i n neurotransmitter and receptor levels. In homozygote mice, dopamine p ersists at least 100 times longer in the extracellular space, explaini ng the biochemical basis of the hyperdopaminergic phenotype and demons trating the critical role of the transporter in regulating neurotransm ission. The dopamine transporter is an obligatory target of cocaine an d amphetamine, as these psychostimulants have no effect on locomotor a ctivity or dopamine release and uptake in mice lacking the transporter .