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Updated: Nov 9, 2025

Electrophysiology on Isolated Brainstem-spinal Cord Preparations from Newborn Rodents Allows Neural Respiratory Network Output Recording
Published on: November 19, 2015
A5 noradrenergic neurons and breathing control in neonate rats
Camila L Taxini1, Danuzia A Marques2, Kênia C Bícego1
1Department of Morphology and Animal Physiology - FCAV, São Paulo State University (UNESP), Via de acesso Paulo Donato Castellane s/n, Jaboticabal, SP, 14870-900, Brazil.
Abstract:
The pontine A5 noradrenergic group contributes to the maturation of the respiratory system before birth in rats. These neurons are connected to the neural network responsible for respiratory rhythmogenesis. In the present study, we investigated the participation of A5 noradrenergic neurons in neonates (P7-8 and P14-15) in the control of ventilation during hypoxia and hypercapnia in in vivo experiments using conjugated saporin anti-dopamine beta-hydroxylase (DβH-SAP) to specifically ablate noradrenergic neurons. Thus, DβH-SAP (420 ng/μL) or saporin (SAP, control) was injected into the A5 region of neonatal male Wistar rats. Hypoxia reduced respiratory variability in control animals; however, A5 lesion prevented this effect in P7-8 rats. Our data suggest that noradrenergic neurons of the A5 region in neonate rats do not participate in the control of ventilation under baseline and hypercapnic conditions, but exert an inhibitory modulation on breathing variability under hypoxic challenge in early life (P7-8).
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