• Swallowing-like activity elici...

*Result*: Swallowing-like activity elicited in neonatal rat medullary slice preparation.

Title:
Swallowing-like activity elicited in neonatal rat medullary slice preparation.
Authors:
Kondo T; First Department of Oral and Maxillofacial Surgery, Graduate School of Dentistry, Osaka University, 1-8 Yamadaoka, Suita, Osaka, Japan. Electronic address: konchan7777@gmail.com., Yamanishi T; First Department of Oral and Maxillofacial Surgery, Graduate School of Dentistry, Osaka University, 1-8 Yamadaoka, Suita, Osaka, Japan; Department of Oral and Maxillofacial Surgery, Osaka Women's and Children's Hospital, Osaka, Japan., Nishio T; First Department of Oral and Maxillofacial Surgery, Graduate School of Dentistry, Osaka University, 1-8 Yamadaoka, Suita, Osaka, Japan; Department of Oral and Maxillofacial Surgery, Osaka Women's and Children's Hospital, Osaka, Japan., Yokota Y; First Department of Oral and Maxillofacial Surgery, Graduate School of Dentistry, Osaka University, 1-8 Yamadaoka, Suita, Osaka, Japan., Seikai T; Department of Oral and Maxillofacial Surgery, Division of Oral Pathobiological Science, Graduate School of Dental Medicine, Faculty of Dental Medicine, Hokkaido University, Hokkaido, Japan., Enomoto A; Department of Oral and Maxillofacial Surgery, Faculty of Medicine, Kindai University, Osaka, Japan., Harada T; Department of Oral and Maxillofacial Surgery, Kansai Rosai Hospital, Osaka, Japan., Tsuji T; First Department of Oral and Maxillofacial Surgery, Graduate School of Dentistry, Osaka University, 1-8 Yamadaoka, Suita, Osaka, Japan., Tanaka S; First Department of Oral and Maxillofacial Surgery, Graduate School of Dentistry, Osaka University, 1-8 Yamadaoka, Suita, Osaka, Japan.
Source:
Brain research [Brain Res] 2024 Aug 15; Vol. 1837, pp. 148955. Date of Electronic Publication: 2024 Apr 26.
Publication Type:
Journal Article
Language:
English
Journal Info:
Publisher: Elsevier/North-Holland Biomedical Press Country of Publication: Netherlands NLM ID: 0045503 Publication Model: Print-Electronic Cited Medium: Internet ISSN: 1872-6240 (Electronic) Linking ISSN: 00068993 NLM ISO Abbreviation: Brain Res Subsets: MEDLINE
Imprint Name(s):
Original Publication: Amsterdam Elsevier/North-Holland Biomedical Press.
MeSH Terms:
Deglutition*/physiology , Deglutition*/drug effects , Medulla Oblongata*/physiology , Medulla Oblongata*/drug effects , Bicuculline*/pharmacology , Bicuculline*/analogs & derivatives , Vagus Nerve*/physiology , Vagus Nerve*/drug effects , Central Pattern Generators*/physiology , Central Pattern Generators*/drug effects , Hypoglossal Nerve*/physiology , Hypoglossal Nerve*/drug effects , Rats, Sprague-Dawley* , Animals, Newborn*, Solitary Nucleus/drug effects ; Solitary Nucleus/physiology ; Animals ; Rats ; Electric Stimulation
Contributed Indexing:
Keywords: Central pattern generators; Deglutition; Electric stimulation; Hypoglossal nerve; Solitary nucleus; Vagus nerve
Substance Nomenclature:
Y37615DVKC (Bicuculline)
40709-69-1 (bicuculline methiodide)
Entry Date(s):
Date Created: 20240428 Date Completed: 20240611 Latest Revision: 20240611
Update Code:
20260130
DOI:
10.1016/j.brainres.2024.148955
PMID:
38679314
Database:
MEDLINE

*Further Information*

*Swallowing is induced by a central pattern generator in the nucleus tractus solitarius (NTS). We aimed to create a medullary slice preparation to elucidate the neural architecture of the central pattern generator of swallowing (Sw-CPG) and record its neural activities. Experiments were conducted on 2-day-old Sprague-Dawley rats (n = 46). The brainstem-spinal cord was transected at the pontomedullary and cervicothoracic junctions; the medulla was sliced transversely at thicknesses of 600, 700, or 800 μm. The rostral end of the slice was 100 μm rostral to the vagus nerve. We recorded hypoglossal nerve activity and electrically stimulated the vagus nerve or microinjected bicuculline methiodide (BIC) into the NTS. The 800-μm slices generated both rhythmic respiratory activity and electrically elicited neural activity. The 700-μm slices generated only respiratory activity, while the 600-μm slices did not generate any neural activity. BIC microinjection into the NTS in 800-μm slices resulted in the typical activity that closely resembled the swallowing activity reported in other experiments. This swallowing-like activity consistently lengthened the respiratory interval. Despite complete inhibition of respiratory activity, weak swallowing-like activity was observed under bath application of a non-NMDA receptor antagonist. Contrastingly, bath application of NMDA receptor antagonists resulted in a complete loss of swallowing-like activity and no change in respiratory activity. These results suggest that the 800-μm medullary slice preparation contains both afferent and efferent neural circuits and pattern generators of swallowing activity. Additionally, NMDA receptors may be necessary for generating swallowing activity. This medullary slice preparation can therefore elucidate Sw-CPG neural networks.
(Copyright © 2024 The Author(s). Published by Elsevier B.V. All rights reserved.)*

*Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.*