In vivo voltammetry in the B3 group of serotonin neurons of the rat medulla oblongata after drug-induced modifications of arterial pressure.
Differential normal pulse voltammetry (DNPV) using an electrochemically treated carbon fiber electrode was applied to the investigation of the in vivo changes in extracellular 5-hydroxyindoleacetic acid (5HIAA) in the B3 group of serotonin neurons during experimental manipulations of arterial pressure. Drug-induced hypertension (phenylephrine infusion) caused, during the infusion, an increase in extracellular 5HIAA concentration which continued to rise, reaching +100% 2 hours after stopping the infusion. In contrast, drug-induced hypotension (sodium nitroprusside infusion) was not associated with any change in extracellular 5HIAA during the infusion while the return to the initial arterial pressure caused a progressive increase in the electrochemical signal, reaching +50% one hour after stopping the infusion. These data show that the extracellular 5HIAA concentration is increased when the arterial pressure increases, a result which suggests that B3 serotonin neurons could have a vasodepressor role in the central regulation of arterial pressure.
Aslanian
V
V
Laboratoire de Neuropharmacologie, UA CNRS 1196, Faculté de Pharmacie, Lyon, France.
Lambas-Senas
L
L
Renaud
B
B
D000493:Allopurinol / Q000494:pharmacology; D000818:Animals; D001545:Benserazide / Q000494:pharmacology*; D001794:Blood Pressure / Q000187:drug effects*; D004558:Electric Stimulation; D006834:Hydrazines / Q000494:pharmacology*; D006897:Hydroxyindoleacetic Acid / Q000378:metabolism; D008297:Male; D008526:Medulla Oblongata / Q000187:drug effects / Q000502:physiology*; D009474:Neurons / Q000187:drug effects / Q000502:physiology*; D010293:Pargyline / Q000494:pharmacology*; D010656:Phenylephrine / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D012016:Reference Values; D012701:Serotonin / Q000502:physiology*
D006834:Hydrazines; D010656:Phenylephrine; D012701:Serotonin; D006897:Hydroxyindoleacetic Acid; D000493:Allopurinol; D001545:Benserazide; D010293:Pargyline