Do only dopaminergic neurons release dopamine?

Yes: Yes, only dopaminergic neurons release dopamine, but there are several dopaminergic pathways in the brain. Dopaminergic neurons in midbrain are the main source of Dopamine in the mammalian cns. Losing these is associated with parkinson's disease. Dopamine neurons are involved with voluntary movement and other behavioral processes such as mood, reward, addiction, psychosis, and stress.