Medicine: D2, the receptor that knows no bounds

Since schizophrenia and the reward system isn't enough, D2 may now play a huge role in depression therapies as well:

The brain's mood, reward, and motivation circuits are mainly governed by dopamine and have been regarded as potential alternative targets for treating depression. Many of these functions are integrated by the medium spiny neurons of the striatum, which lie below the cortex of the brain and respond to dopamine. Dopamine exerts its function in target cells through five known subtypes of dopamine receptors to regulate motor control, stereotypic behaviors, arousal, mood, motivation, and endocrine function. Impairment in the function of dopamine D2 receptor is implicated in various neuropsychiatric disorders including schizophrenia and drug addiction.

I question somewhat whether therapies targeted specifically to dopamine pathways will be any more effective than current treatments, since neurotransmitters do not live on islands. Serotonin, dopamine, and norepinephrine all live in the same neighborhood, and their regulation seems likely related to one another. And given that SSRIs obviously do not actually work because they are SSRIs, I figure we might already be targeting dopaminergic pathways without even realizing it. Still, three cheers for dopamine!