Inhibition of rat nucleus tractus solitarius neurones by activation of 5-HT2C receptors.
In vivo, nucleus tractus solitarius (NTS) neurones receiving monosynaptic vagal input and inactive intermediate neurones were inhibited by both DOI and a selective 5-HT2C receptor agonist, MK-212. Cells receiving a more polysynaptic input were excited by DOI and although MK-212 also excited a few of these cells, the majority of cells in these groups were unaffected by MK-212. The inhibitory, but not the excitatory actions of both MK-212 and DOI were prevented by a selective 5-HT2C receptor antagonist, RS-102221. In contrast, most dorsal vagal preganglionic neurones were unaffected by application of either DOI or MK-212, the few remaining cells being excited by both agonists. These data demonstrate that DOI-evoked inhibition of NTS cells activated by vagal afferent input and DOI-evoked excitation of vagal preganglionic neurones is mediated by 5-HT2C receptors.
Sévoz-Couche
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C
Department of Physiology, Royal Free and University College Medical School, London, UK.
Spyer
K M
KM
Jordan
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D000662:Amphetamines / Q000494:pharmacology; D000818:Animals; D005071:Evoked Potentials / Q000502:physiology; D008024:Ligands; D008297:Male; D009433:Neural Inhibition / Q000502:physiology*; D009474:Neurons / Q000187:drug effects / Q000502:physiology*; D011719:Pyrazines / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D044405:Receptor, Serotonin, 5-HT2C; D011985:Receptors, Serotonin / Q000187:drug effects / Q000502:physiology*; D012702:Serotonin Antagonists / Q000494:pharmacology; D017366:Serotonin Receptor Agonists / Q000494:pharmacology; D017552:Solitary Nucleus / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D013141:Spiro Compounds / Q000494:pharmacology; D013449:Sulfonamides / Q000494:pharmacology; D014630:Vagus Nerve / Q000502:physiology
C107821:8-(5-(5-amino-2,4-dimethoxyphenyl)-5-oxopentyl)-1,3,8-triazaspiro(4.5)decane-2,4-dione; D000662:Amphetamines; D008024:Ligands; D011719:Pyrazines; D044405:Receptor, Serotonin, 5-HT2C; D011985:Receptors, Serotonin; D012702:Serotonin Antagonists; D017366:Serotonin Receptor Agonists; D013141:Spiro Compounds; D013449:Sulfonamides; C014896:6-chloro-2-(1-piperazinyl)pyrazine; C015952:4-iodo-2,5-dimethoxyphenylisopropylamine