Dopamine (DA) is a neurotransmitter in the central nervous system (CNS) and has been implicated in the pathogenesis of various diseases of motor functions and psychiatric conditions. Dopamine is also the key modulator for motivational behavior and brain reward system and regulates food intake as well. It has some neuroendocrine function too. It is noteworthy that dopamine has so many diverse roles in the CNS. DA has various pathways such as the Nigrostriatal pathway, Mesolimbic pathway, Mesocortical pathway and Tuberohypophyseal pathway. It has D1, D2, D3, D4 and D5 metabotropic receptors and interacts with cholinergic, GABAergic, opioidergic and glutamatergic systems. DA also activates diverse second messengers and pathways. These complicated interactions partly explain its diverse actions. The aim of the present chapter is to summarize data on the contribution of DA in the pathogenesis of many conditions such as Parkinson’s disease, Schizophrenia, Attention Deficit Hyperactivity Disorder and addiction.
Part of the book: Pathology