Posted 04 December 2006 - 02:25 PM
when neurotransmitters are released, they hop across the synapse of a neuron and onto the receptors of the post-synaptic neuron. a transporter protein then ferries the neurotransmitter back to the pre-synaptic neuron, in order to recycle it, and also to reduce the transmitters action at this receptor. this process is called reuptake. a DA reuptake inhibitor means that the transporter protein is blocked, which means it can't transport the transmitter back to the pre-synaptic neuron. this causes > levels of dopamine.
i don't think i can describe it in any simpler terms.
re mode of action, it's unclear what you're asking. what does it do? it's best to find out which parts of the brain have the highest density of dopamine receptors, and to which parts of the brain these neurons send their projections. increased dopamine would affect motivation, salience, locomotor activity, movement, amongst others