Mapping responses to focal injections of bicuculline in the lateral parafacial region identifies core regions for maximal generation of active expiration.

Autor:	Pisanski A; Department of Physiology, University of Alberta, Edmonton, Canada., Prostebby M; Neuroscience and Mental Health Institute, University of Alberta, Edmonton, Canada., Dickson CT; Department of Physiology, University of Alberta, Edmonton, Canada.; Neuroscience and Mental Health Institute, University of Alberta, Edmonton, Canada.; Department of Psychology, University of Alberta, Edmonton, Canada.; Department of Anesthesiology and Pain Medicine, University of Alberta, Edmonton, Canada.; Women and Children's Health Research Institute, University of Alberta, Edmonton, Canada., Pagliardini S; Department of Physiology, University of Alberta, Edmonton, Canada.; Neuroscience and Mental Health Institute, University of Alberta, Edmonton, Canada.; Department of Anesthesiology and Pain Medicine, University of Alberta, Edmonton, Canada.; Women and Children's Health Research Institute, University of Alberta, Edmonton, Canada.
Jazyk:	angličtina
Zdroj:	ELife [Elife] 2024 Jul 17; Vol. 13. Date of Electronic Publication: 2024 Jul 17.
DOI:	10.7554/eLife.94276
Abstrakt:	The lateral parafacial area (pFL) is a crucial region involved in respiratory control, particularly in generating active expiration through an expiratory oscillatory network. Active expiration involves rhythmic abdominal (ABD) muscle contractions during late-expiration, increasing ventilation during elevated respiratory demands. The precise anatomical location of the expiratory oscillator within the ventral medulla's rostro-caudal axis is debated. While some studies point to the caudal tip of the facial nucleus (VIIc) as the oscillator's core, others suggest more rostral areas. Our study employed bicuculline (a γ-aminobutyric acid type A [GABA-A] receptor antagonist) injections at various pFL sites (-0.2 mm to +0.8 mm from VIIc) to investigate the impact of GABAergic disinhibition on respiration. These injections consistently elicited ABD recruitment, but the response strength varied along the rostro-caudal zone. Remarkably, the most robust and enduring changes in tidal volume, minute ventilation, and combined respiratory responses occurred at more rostral pFL locations (+0.6/+0.8 mm from VIIc). Multivariate analysis of the respiratory cycle further differentiated between locations, revealing the core site for active expiration generation with this experimental approach. Our study advances our understanding of neural mechanisms governing active expiration and emphasizes the significance of investigating the rostral pFL region. Competing Interests: AP, MP, CD, SP No competing interests declared (© 2024, Pisanski et al.)
Databáze:	MEDLINE
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