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The effects of intragastric infusion of umami solutions on amygdalar and lateral hypothalamic neurons in rats
Previous behavioral studies have suggested that l-glutamate, an umami substance, is detected in the gut, and that this information regarding glutamate is conveyed from the gut to the amygdala and the lateral hypothalamus (LH) through the vagus nerve to establish glutamate preference. In this study,...
Autores principales: | , , , , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
John Wiley & Sons, Ltd
2015
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4632945/ https://www.ncbi.nlm.nih.gov/pubmed/26438732 http://dx.doi.org/10.14814/phy2.12545 |
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author | Davaasuren, Munkhzul Matsumoto, Jumpei Chinzorig, Choijiljav Nakamura, Tomoya Takamura, Yusaku Patrono, Enrico Kondoh, Takashi Ono, Taketoshi Nishijo, Hisao |
author_facet | Davaasuren, Munkhzul Matsumoto, Jumpei Chinzorig, Choijiljav Nakamura, Tomoya Takamura, Yusaku Patrono, Enrico Kondoh, Takashi Ono, Taketoshi Nishijo, Hisao |
author_sort | Davaasuren, Munkhzul |
collection | PubMed |
description | Previous behavioral studies have suggested that l-glutamate, an umami substance, is detected in the gut, and that this information regarding glutamate is conveyed from the gut to the amygdala and the lateral hypothalamus (LH) through the vagus nerve to establish glutamate preference. In this study, we investigated the roles of the amygdala and LH in the information processing of gut glutamate. We recorded the activity of amygdalar and LH neurons during the intragastric administration of five test solutions (monosodium l-glutamate [MSG, 60 mmol/L]; inosine monophosphate [IMP, 60 mmol/L]; a mixture of MSG and IMP; NaCl [60 mmol/L]; or physiological saline) in intact and subdiaphragmatic vagotomized awake rats. In intact rats, 349 and 189 neurons were recorded from the amygdala and LH, respectively, while in vagotomized rats, 104 and 90 neurons were recorded from the amygdala and LH, respectively. In intact rats, similar percentages of neurons (30–60%) in the amygdala and LH responded to the intragastric infusion of the solutions. Vagotomy significantly altered responses to the MSG and NaCl solutions. In particular, vagotomy suppressed the inhibitory responses to the NaCl solution. Furthermore, vagotomy increased the response similarity between the MSG and NaCl solutions, suggesting that vagotomy impaired the coding of the postingestive consequences of the MSG solution in the amygdala and LH, which are unique for glutamate. The present results provide the first neurophysiological evidence that amygdalar and LH neurons process glutamate signals from the gut. |
format | Online Article Text |
id | pubmed-4632945 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2015 |
publisher | John Wiley & Sons, Ltd |
record_format | MEDLINE/PubMed |
spelling | pubmed-46329452015-11-09 The effects of intragastric infusion of umami solutions on amygdalar and lateral hypothalamic neurons in rats Davaasuren, Munkhzul Matsumoto, Jumpei Chinzorig, Choijiljav Nakamura, Tomoya Takamura, Yusaku Patrono, Enrico Kondoh, Takashi Ono, Taketoshi Nishijo, Hisao Physiol Rep Original Research Previous behavioral studies have suggested that l-glutamate, an umami substance, is detected in the gut, and that this information regarding glutamate is conveyed from the gut to the amygdala and the lateral hypothalamus (LH) through the vagus nerve to establish glutamate preference. In this study, we investigated the roles of the amygdala and LH in the information processing of gut glutamate. We recorded the activity of amygdalar and LH neurons during the intragastric administration of five test solutions (monosodium l-glutamate [MSG, 60 mmol/L]; inosine monophosphate [IMP, 60 mmol/L]; a mixture of MSG and IMP; NaCl [60 mmol/L]; or physiological saline) in intact and subdiaphragmatic vagotomized awake rats. In intact rats, 349 and 189 neurons were recorded from the amygdala and LH, respectively, while in vagotomized rats, 104 and 90 neurons were recorded from the amygdala and LH, respectively. In intact rats, similar percentages of neurons (30–60%) in the amygdala and LH responded to the intragastric infusion of the solutions. Vagotomy significantly altered responses to the MSG and NaCl solutions. In particular, vagotomy suppressed the inhibitory responses to the NaCl solution. Furthermore, vagotomy increased the response similarity between the MSG and NaCl solutions, suggesting that vagotomy impaired the coding of the postingestive consequences of the MSG solution in the amygdala and LH, which are unique for glutamate. The present results provide the first neurophysiological evidence that amygdalar and LH neurons process glutamate signals from the gut. John Wiley & Sons, Ltd 2015-10-05 /pmc/articles/PMC4632945/ /pubmed/26438732 http://dx.doi.org/10.14814/phy2.12545 Text en © 2015 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of the American Physiological Society and The Physiological Society. http://creativecommons.org/licenses/by/4.0/ This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. |
spellingShingle | Original Research Davaasuren, Munkhzul Matsumoto, Jumpei Chinzorig, Choijiljav Nakamura, Tomoya Takamura, Yusaku Patrono, Enrico Kondoh, Takashi Ono, Taketoshi Nishijo, Hisao The effects of intragastric infusion of umami solutions on amygdalar and lateral hypothalamic neurons in rats |
title | The effects of intragastric infusion of umami solutions on amygdalar and lateral hypothalamic neurons in rats |
title_full | The effects of intragastric infusion of umami solutions on amygdalar and lateral hypothalamic neurons in rats |
title_fullStr | The effects of intragastric infusion of umami solutions on amygdalar and lateral hypothalamic neurons in rats |
title_full_unstemmed | The effects of intragastric infusion of umami solutions on amygdalar and lateral hypothalamic neurons in rats |
title_short | The effects of intragastric infusion of umami solutions on amygdalar and lateral hypothalamic neurons in rats |
title_sort | effects of intragastric infusion of umami solutions on amygdalar and lateral hypothalamic neurons in rats |
topic | Original Research |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4632945/ https://www.ncbi.nlm.nih.gov/pubmed/26438732 http://dx.doi.org/10.14814/phy2.12545 |
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