Fig. 1.

A schematic of inhibitory inputs and astrocyte processes surrounding dopamine (DA) neurons in the ventral tegmental area (VTA). As depicted, in addition to excitatory inputs, many elements are present in the local signalling milieu. Inhibitory inputs arising from multiple sources synapse onto GABAA and GABAB receptors on DA neurons. Astrocytes take up and release several signalling molecules, including glutamate, ATP, and D-serine. These processes are likely exerting important influences on the output and plasticity of DA neurons.