Functional implications of dopamine D1 vs. D2 receptors: A 'prepare and select' model of the striatal direct vs. indirect pathways.

•A new model of dopamine function in the basal ganglia.•Encoding of reward association strength in the direct and indirect pathways.•Direct pathways encode using LTP mechanisms.•Indirect pathways encode using receptor internalisation.•Combined these pathways operate as a ‘prepare and select’ system.