Inhibitory serotonergic effects on rostral ventrolateral medullary neurons.
In rats anaesthetised with urethane, iontophoretic application of 5-hydroxytryptamine (5-HT) and the 5-HT1A agonists buspirone, flesinoxan and 8-hydroxy-2-(di-n-propylamino)-tetralin inhibited ongoing or amino-acid-evoked activity of neurons in the rostral ventrolateral medulla (RVLM) including barosensitive cells with spinally projecting axons. More than 90% of cells tested were inhibited by these agonists. In 5/9 cells the inhibition was reduced after intravenous spiperone (0.6 mg/kg). These results suggest that the sympatho-inhibitory effects produced by microinjection of 5-HT1A agonists into the RVLM are due to a direct inhibitory action on neurons that send excitatory projections to the spinal sympathetic outflow.
Wang
W H
WH
Department of Physiology, The Medical School, Birmingham, UK.
Lovick
T A
TA
D000818:Animals; D008297:Male; D008526:Medulla Oblongata / Q000166:cytology / Q000502:physiology*; D009433:Neural Inhibition; D009474:Neurons / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D012701:Serotonin / Q000494:pharmacology / Q000502:physiology*; D012702:Serotonin Antagonists / Q000494:pharmacology; D017366:Serotonin Receptor Agonists / Q000494:pharmacology; D013116:Spinal Cord / Q000502:physiology; D009435:Synaptic Transmission
D012702:Serotonin Antagonists; D017366:Serotonin Receptor Agonists; D012701:Serotonin