Abstract
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.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Amphetamines / pharmacology
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Animals
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Evoked Potentials / physiology
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Ligands
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Male
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Neural Inhibition / physiology*
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Neurons / drug effects
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Neurons / physiology*
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Pyrazines / pharmacology
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Rats
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Rats, Sprague-Dawley
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Receptor, Serotonin, 5-HT2C
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Receptors, Serotonin / drug effects
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Receptors, Serotonin / physiology*
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Serotonin Antagonists / pharmacology
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Serotonin Receptor Agonists / pharmacology
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Solitary Nucleus / cytology
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Solitary Nucleus / drug effects
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Solitary Nucleus / physiology*
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Spiro Compounds / pharmacology
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Sulfonamides / pharmacology
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Vagus Nerve / physiology
Substances
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8-(5-(5-amino-2,4-dimethoxyphenyl)-5-oxopentyl)-1,3,8-triazaspiro(4.5)decane-2,4-dione
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Amphetamines
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Ligands
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Pyrazines
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Receptor, Serotonin, 5-HT2C
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Receptors, Serotonin
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Serotonin Antagonists
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Serotonin Receptor Agonists
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Spiro Compounds
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Sulfonamides
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6-chloro-2-(1-piperazinyl)pyrazine
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4-iodo-2,5-dimethoxyphenylisopropylamine