Serotonin-induced inward current in rat facial motoneurons: evidence for mediation by G proteins but not protein kinase C.
The 5-HT-induced inward current in rat facial motoneurons was rendered irreversible by intracellular GTP gamma S, an hydrolysis-resistant analog of guanosine 5'-triphosphate which sustains G protein activation. Conversely, the 5-HT response was reduced by GDP beta S, an analog of guanosine 5'-diphosphate which interferes with G protein activation. Inhibitors of protein kinase C enhanced the 5-HT-induced inward current. Thus, the slow inward current induced by 5-HT in facial motoneurons appears to be mediated by G proteins but modulated negatively by protein kinase C.
Aghajanian
G K
GK
Department of Psychiatry, Yale University School of Medicine, New Haven, CT 06508.
D019307:1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine; D000818:Animals; D001921:Brain / Q000187:drug effects / Q000502:physiology*; D004553:Electric Conductivity; D005154:Facial Nerve / Q000502:physiology*; D019204:GTP-Binding Proteins / Q000502:physiology*; D016244:Guanosine 5'-O-(3-Thiotriphosphate); D006153:Guanosine Diphosphate / Q000031:analogs & derivatives / Q000494:pharmacology; D006160:Guanosine Triphosphate / Q000031:analogs & derivatives / Q000494:pharmacology; D066298:In Vitro Techniques; D007546:Isoquinolines / Q000494:pharmacology; D008297:Male; D009046:Motor Neurons / Q000187:drug effects / Q000502:physiology*; D010703:Phorbol Esters / Q000494:pharmacology; D010879:Piperazines / Q000494:pharmacology; D011493:Protein Kinase C / Q000037:antagonists & inhibitors / Q000378:metabolism*; D051381:Rats; D012701:Serotonin / Q000494:pharmacology*; D013873:Thionucleotides / Q000494:pharmacology
D007546:Isoquinolines; D010703:Phorbol Esters; D010879:Piperazines; D013873:Thionucleotides; D006153:Guanosine Diphosphate; C008874:phorbol-12,13-diacetate; D012701:Serotonin; D016244:Guanosine 5'-O-(3-Thiotriphosphate); C023427:guanosine 5'-O-(2-thiodiphosphate); D019307:1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine; D006160:Guanosine Triphosphate; D011493:Protein Kinase C; D019204:GTP-Binding Proteins