| Effects of 5-HT alone and its interaction with TRH on neurons in rat dorsal motor nucleus of the vagus. | |
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MedLine Citation:
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PMID: 7864126 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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The purpose of this study was to determine whether exposure to thyrotropin-releasing hormone (TRH) enhances the excitatory effect of 5-hydroxytryptamine (5-HT) on motoneurons of the dorsal motor nucleus of the vagus (DMV) as described in whole animal studies. For this purpose we used the patch-clamp technique applied to rat brain stem slices. Exposure of DMV motoneurons to concentrations of 5-HT (0.1-3 microM) resulted in a concentration-related increase in spontaneous firing rate. As previously described by Travagli et al. [Am. J. Physiol. 263 (Gastrointest. Liver Physiol. 26): G508-G517, 1992], TRH (1-30 microM) increased action potential firing rate. Indeed, when TRH perfusion increased the firing rate, addition of 5-HT to the perfusing solution exerted no further excitation of the DMV motoneuron, indicating that there was no summation of response. Studies using whole cell current recordings showed a common action of 5-HT and TRH in antagonizing the Ca(2+)-dependent afterhyperpolarizing current (IAHP). Again, interaction studies between TRH and 5-HT indicated no enhancing effect of TRH on 5-HT-induced antagonism of IAHP. In conclusion, our data indicated that the enhancement of 5-HT-induced excitation of DMV motoneurons by TRH described by in vivo rat experiments is not due to an interaction of TRH and 5-HT directly on the DMV motoneuron. |
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Authors:
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R A Travagli; R A Gillis |
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Publication Detail:
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Type: In Vitro; Journal Article; Research Support, U.S. Gov't, P.H.S. |
Journal Detail:
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Title: The American journal of physiology Volume: 268 ISSN: 0002-9513 ISO Abbreviation: Am. J. Physiol. Publication Date: 1995 Feb |
Date Detail:
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Created Date: 1995-03-21 Completed Date: 1995-03-21 Revised Date: 2007-11-14 |
Medline Journal Info:
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Nlm Unique ID: 0370511 Medline TA: Am J Physiol Country: UNITED STATES |
Other Details:
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Languages: eng Pagination: G292-9 Citation Subset: IM |
Affiliation:
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Department of Pharmacology, Georgetown University School of Medicine, Washington, DC 20007. |
Export Citation:
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APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
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Animals Drug Interactions Electrophysiology Medulla Oblongata / cytology, drug effects*, physiology Neurons / drug effects*, physiology Rats Rats, Sprague-Dawley Serotonin / pharmacology* Thyrotropin-Releasing Hormone / pharmacology* Time Factors Vagus Nerve / physiology* |
| Grant Support | |
ID/Acronym/Agency:
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P01 NS-28130/NS/NINDS NIH HHS |
| Chemical | |
Reg. No./Substance:
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24305-27-9/Thyrotropin-Releasing Hormone; 50-67-9/Serotonin |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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