Editing Dopamine (section)

===Nausea===
Nausea and [[vomiting]] are largely determined by activity in the [[area postrema]] in the [[medulla oblongata|medulla]] of the [[brainstem]], in a region known as the [[chemoreceptor trigger zone]].<ref name=Flake>{{cite journal | vauthors = Flake ZA, Scalley RD, Bailey AG | title = Practical selection of antiemetics | journal = American Family Physician | volume = 69 | issue = 5 | pages = 1169–74 | date = March 2004 | pmid = 15023018 | url = http://www.aafp.org/afp/2004/0301/p1169.html }}</ref> This area contains a large population of type D<sub>2</sub> dopamine receptors.<ref name=Flake/> Consequently, drugs that activate D<sub>2</sub> receptors have a high potential to cause nausea.<ref name=Flake/> This group includes some medications that are administered for Parkinson's disease, as well as other [[dopamine agonists]] such as [[apomorphine]].<ref name=Connolly>{{cite journal | vauthors = Connolly BS, Lang AE | title = Pharmacological treatment of Parkinson disease: a review | journal = JAMA | volume = 311 | issue = 16 | pages = 1670–83 | year = 2014 | pmid = 24756517 | doi = 10.1001/jama.2014.3654 }}</ref> In some cases, D<sub>2</sub>-receptor antagonists such as [[metoclopramide]] are useful as [[anti-emetics|anti-nausea drugs]].<ref name=Flake/>

'''Fear and anxiety'''

Simultaneous [[positron emission tomography]] (PET) and [[functional magnetic resonance imaging]] (fMRI), have shown that the amount of dopamine release is dependent on the strength of conditioned fear response and is linearly coupled to learning-induced activity in the amygdala.<ref>{{cite journal | vauthors = Frick A, Björkstrand J, Lubberink M, Eriksson A, Fredrikson M, Åhs F | title = Dopamine and fear memory formation in the human amygdala | journal = Molecular Psychiatry | volume = 27 | issue = 3 | pages = 1704–1711 | date = March 2022 | pmid = 34862441 | doi = 10.1038/s41380-021-01400-x | pmc = 9095491 }}</ref> Dopamine is generally linked to reward learning, but it also plays a key role in fear learning and extinction by helping to form, store and update fear memories through its interaction with other brain regions like amygdala, ventromedial prefrontal cortex and striatum.<ref>{{cite journal | vauthors = Hamati R, Ahrens J, Shvetz C, Holahan MR, Tuominen L | title = 65 years of research on dopamine's role in classical fear conditioning and extinction: A systematic review | journal = The European Journal of Neuroscience | volume = 59 | issue = 6 | pages = 1099–1140 | date = March 2024 | pmid = 37848184 | doi = 10.1111/ejn.16157 | doi-access = free }}</ref>