Carbon monoxide and the <scp>CNS</scp>: challenges and achievements

<jats:sec><jats:label /><jats:p>Haem oxygenase (<jats:styled-content style="fixed-case">HO</jats:styled-content>) and its product carbon monoxide (<jats:styled-content style="fixed-case">CO</jats:styled-content>) are associated with cytoprotection and maintenance of homeostasis in several different organs and tissues. This review focuses upon the role of exogenous and endogenous <jats:styled-content style="fixed-case">CO</jats:styled-content> (via <jats:styled-content style="fixed-case">HO</jats:styled-content> activity and expression) in various <jats:styled-content style="fixed-case">CNS</jats:styled-content> pathologies, based upon data from experimental models, as well as from some clinical data on human patients. The pathophysiological conditions reviewed are cerebral ischaemia, chronic neurodegenerative diseases (<jats:styled-content style="fixed-case">A</jats:styled-content>lzheimer's and <jats:styled-content style="fixed-case">P</jats:styled-content>arkinson's diseases), multiple sclerosis and pain. Among these pathophysiological conditions, a variety of cellular mechanisms and processes are considered, namely cytoprotection, cell death, inflammation, cell metabolism, cellular redox responses and vasomodulation, as well as the different targeted neural cells. Finally, novel potential methods and strategies for delivering exogenous <jats:styled-content style="fixed-case">CO</jats:styled-content> as a drug are discussed, particularly approaches based upon <jats:styled-content style="fixed-case">CO</jats:styled-content>‐releasing molecules, their limitations and challenges. The diagnostic and prognostic value of <jats:styled-content style="fixed-case">HO</jats:styled-content> expression in clinical use for brain pathologies is also addressed.</jats:p></jats:sec><jats:sec><jats:title>Linked Articles</jats:title><jats:p>This article is part of a themed section on Pharmacology of the Gasotransmitters. To view the other articles in this section visit <jats:ext-link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://dx.doi.org/10.1111/bph.2015.172.issue-6">http://dx.doi.org/10.1111/bph.2015.172.issue-6</jats:ext-link></jats:p></jats:sec>