Midbrain serotonergic neurons are central pH chemoreceptors.
Serotonergic neurons in the medulla are central respiratory chemoreceptors. Here we show that serotonergic neurons in the midbrain of rats are also highly chemosensitive to small changes in CO2/pH and are closely associated with large penetrating arteries. We propose that midbrain raphé neurons are sensors of blood CO2 that maintain pH homeostasis by inducing arousal, anxiety and changes in cerebrovascular tone in response to respiratory acidosis.
D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D000831:Animals, Newborn; D002245:Carbon Dioxide / Q000097:blood / Q000494:pharmacology; D002478:Cells, Cultured; D002628:Chemoreceptor Cells / Q000187:drug effects / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D006863:Hydrogen-Ion Concentration; D007150:Immunohistochemistry; D066298:In Vitro Techniques; D008239:Lysine / Q000031:analogs & derivatives* / Q000378:metabolism; D009474:Neurons / Q000187:drug effects / Q000378:metabolism*; D018408:Patch-Clamp Techniques; D011903:Raphe Nuclei / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D051381:Rats; D012701:Serotonin / Q000378:metabolism*; D014365:Tryptophan Hydroxylase / Q000378:metabolism
D002245:Carbon Dioxide; D012701:Serotonin; D014365:Tryptophan Hydroxylase; C013411:biocytin; D008239:Lysine