Editing Dopaminergic pathways (section)

{{short description|Projection neurons in the brain that synthesize and release dopamine}}
[[File:Dopaminergic pathways.svg|thumb|right|The main dopaminergic pathways of the [[human brain]]]]
'''Dopaminergic pathways''' ('''dopamine pathways''', '''dopaminergic projections''') in the [[human brain]] are involved in both physiological and behavioral processes including [[motion|movement]], [[cognition]], [[executive functions]], [[Reward system|reward]], [[motivation]], and [[Neuroendocrine cell|neuroendocrine control]].<ref>{{cite journal | vauthors = Alcaro A, Huber R, Panksepp J | title = Behavioral functions of the mesolimbic dopaminergic system: an affective neuroethological perspective | journal = Brain Research Reviews | volume = 56 | issue = 2 | pages = 283–321 | date = December 2007 | pmid = 17905440 | pmc = 2238694 | doi = 10.1016/j.brainresrev.2007.07.014 }}</ref> Each pathway is a set of [[projection neuron|projection neurons]], consisting of individual dopaminergic neurons.  

The four major dopaminergic pathways are the [[mesolimbic pathway]], the [[mesocortical pathway]], the [[nigrostriatal pathway]], and the [[tuberoinfundibular pathway]]. The mesolimbic pathway and the mesocortical pathway form the mesocorticolimbic system. Two other dopaminergic pathways to be considered are the [[hypothalamospinal tract]] and the [[incertohypothalamic pathway]].

[[Parkinson's disease]], [[attention deficit hyperactivity disorder]] (ADHD), [[substance use disorder]]s ([[addiction]]), and [[restless legs syndrome]] (RLS) can be attributed to dysfunction in specific dopaminergic pathways.  

The dopamine neurons of the dopaminergic pathways synthesize and release the [[neurotransmitter]] [[dopamine]].<ref name="urlBeyond the Reward Pathway">{{cite web |title=Beyond the Reward Pathway | work = Learn Genetics | publisher = University of Utah |url=http://learn.genetics.utah.edu/content/addiction/reward/pathways.html|url-status=dead |archive-url= https://web.archive.org/web/20100209020641/http://learn.genetics.utah.edu/content/addiction/reward/pathways.html |archive-date=2010-02-09 |access-date=2009-10-23 }}</ref><ref name="projection">{{cite book | vauthors = Le Moal M | chapter = Mesocorticolimbic Dopaminergic Neurons: Functional and Regulatory Roles |url= http://www.acnp.org/g4/gn401000025/ch025.html|url-status=dead|archive-url= https://web.archive.org/web/20180205211300/http://www.acnp.org/g4/gn401000025/ch025.html |archive-date=5 February 2018 | veditors = Bloom FE, Kupfer DJ |title=Psychopharmacology: the fourth generation of progress |date=1995 |publisher=Raven Press |location=New York |isbn=978-0-7817-0166-2 }}</ref> Enzymes [[tyrosine hydroxylase]] and [[dopa decarboxylase]] are required for dopamine synthesis.<ref name = "Harsing_2000">{{cite book | vauthors = Harsing LG | chapter = Dopamine and the Dopaminergic Systems of the Brain |date=2008 | title = Handbook of Neurochemistry and Molecular Neurobiology|pages=149–170 | veditors = Lajtha A, Vizi ES |place=Boston, MA|publisher=Springer US |doi=10.1007/978-0-387-30382-6_7|isbn=978-0-387-30351-2 }}</ref> These enzymes are both produced in the [[Soma (biology)|cell bodies]] of dopamine neurons. Dopamine is stored in the cytoplasm and vesicles in axon terminals. Dopamine release from vesicles is triggered by action potential propagation-induced membrane depolarization.<ref name = "Harsing_2000" /> The [[axon]]s of dopamine neurons extend the entire length of their designated pathway.