Dopamine — GABA Interactions

In contrast to γ-aminobutyric acid (GABA)ergic neurons which are ubiquitous in the brain, dopaminergic systems are restricted to a few well-characterized pathways. Dopaminergic cell bodies are for the most part concentrated in the mesencephalon and give rise to three main pathways: the nigrostriatal (or mesostriatal) system, innervating the caudate putamen (or striatum) and other regions of the basal ganglia, the mesolimbic system, innervating the nucleus accumbens and other parts of the limbic system, and the mesocortical pathway, innervating the prefrontal cortex (see Chesselet 1999). All these dopaminergic systems interact with GABAergic neurons both at the level of their cell bodies and in their terminal regions. However, the mesostriatal system has been more extensively studied because the loss of these dopaminergic neurons leads to Parkinson’s disease, and GABAergic neurons normally controlled by nigrostriatal dopamine are thought to play a critical role in the symptoms of the disease (see Chesselet and Delfs 1996).