Uncovering the neural control of laryngeal activity and subglottic pressure in anaesthetized rats: insights from mesencephalic regions

• Published in: Pflügers Archiv Vol. 476; no. 8; pp. 1235 - 1247
• Main Authors: González-García, M., Carrillo-Franco, L., Morales-Luque, C., Ponce-Velasco, M., Gago, B., Dawid-Milner, M. S., López-González, M. V.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.08.2024; Springer Nature B.V
• Subjects: Animals; Biomedical and Life Sciences; Biomedicine; c-Fos protein; Cell Biology; Electric Stimulation - methods; Electrical stimuli; Forkhead Transcription Factors - metabolism; Foxp2 protein; Glutamic Acid - metabolism; Human Physiology; Immunoreactivity; Larynx; Larynx - metabolism; Larynx - physiology; Male; Medulla Oblongata - metabolism; Medulla Oblongata - physiology; Molecular Medicine; Neuroscience; Neurosciences; Nucleus ambiguus; Periaqueductal Gray - metabolism; Periaqueductal Gray - physiology; Periaqueductal gray area; Physiology; Pressure; Proteins; Proto-Oncogene Proteins c-fos - metabolism; Rats; Rats, Sprague-Dawley; Receptors; Respiration; Substantia grisea; Tyrosine 3-monooxygenase; Tyrosine 3-Monooxygenase - metabolism; Dorsolateral periaqueductal gray matter; Subglottic pressure; Rat; Nucleus ambiguous; Laryngeal motoneurons; Central cardiorespiratory control
• ISSN: 0031-6768; 1432-2013; 1432-2013
• DOI: 10.1007/s00424-024-02976-3

To assess the possible interactions between the dorsolateral periaqueductal gray matter (dlPAG) and the different domains of the nucleus ambiguus (nA), we have examined the pattern of double-staining c-Fos/FoxP2 protein immunoreactivity (c-Fos-ir/FoxP2-ir) and tyrosine hydroxylase (TH) throughout the rostrocaudal extent of nA in spontaneously breathing anaesthetised male Sprague–Dawley rats during dlPAG electrical stimulation. Activation of the dlPAG elicited a selective increase in c-Fos-ir with an ipsilateral predominance in the somatas of the loose ( p  < 0.05) and compact formation ( p  < 0.01) within the nA and confirmed the expression of FoxP2 bilaterally in all the domains within the nA. A second group of experiments was made to examine the importance of the dlPAG in modulating the laryngeal response evoked after electrical or chemical (glutamate) dlPAG stimulations. Both electrical and chemical stimulations evoked a significant decrease in laryngeal resistance (subglottal pressure) ( p  < 0.001) accompanied with an increase in respiratory rate together with a pressor and tachycardic response. The results of our study contribute to new data on the role of the mesencephalic neuronal circuits in the control mechanisms of subglottic pressure and laryngeal activity.