Intragastric gavage with denatonium benzoate acutely induces neuronal activation in the solitary tract nucleus via the vagal afferent pathway
J. vet. sci
; J. vet. sci;: 459-464, 2014.
Article
in En
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| ID: wpr-24555
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ABSTRACT
Natural toxic substances have a bitter taste and their ingestion sends signals to the brain leading to aversive oral sensations. In the present study, we investigated chronological changes in c-Fos immunoreactivity in the nucleus tractus solitarius (NTS) to study the bitter taste reaction time of neurons in the NTS. Equal volumes (0.5 mL) of denatonium benzoate (DB), a bitter tastant, or its vehicle (distilled water) were administered to rats intragastrically. The rats were sacrificed at 0, 0.5, 1, 2, 4, 8, or 16 h after treatment. In the vehicle-treated group, the number of c-Fos-positive nuclei started to increase 0.5 h after treatment and peaked 2 h after gavage. In contrast, the number of c-Fos-positive nuclei in the DB-treated group significantly increased 1 h after gavage. Thereafter, the number of c-Fos immunoreactive nuclei decreased over time. The number of c-Fos immunoreactive nuclei in the NTS was also increased in a dose-dependent manner 1 h after gavage. Subdiaphragmatic vagotomy significantly decreased DB-induced neuronal activation in the NTS. These results suggest that intragastric DB increases neuronal c-Fos expression in the NTS 1 h after gavage and this effect is mediated by vagal afferent fibers.
Key words
Full text:
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Index:
WPRIM
Main subject:
Vagus Nerve
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Afferent Pathways
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Adjuvants, Immunologic
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Proto-Oncogene Proteins c-fos
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Rats, Sprague-Dawley
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Solitary Nucleus
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Receptors, G-Protein-Coupled
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Quaternary Ammonium Compounds
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Injections
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Ligands
Limits:
Animals
Language:
En
Journal:
J. vet. sci
Year:
2014
Type:
Article