Pre- and post-inspiratory neurons change their firing properties in female rats exposed to chronic intermittent hypoxia

Autor(es)

Souza, George M. P. R. ^[1] ; Barnett, William H. ^{[2, 3]} ; Amorim, Mateus R. ^[1] ; Lima-Silveira, Ludmila ^[1] ; Moraes, Davi J. A. ^[1] ; Molkov, I, Yaroslav ; Machado, Benedito H. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Dept Physiol, Sch Med Ribeirao Preto, Ribeirao Preto, SP - Brazil

^[2] I, Georgia State Univ, Dept Math & Stat, Atlanta, GA 30303 - USA

^[3] I, Georgia State Univ, Neurosci Inst, Atlanta, GA 30303 - USA

• Tipo de documento: Artigo Científico
• Fonte: Neuroscience; v. 406, p. 467-486, MAY 15 2019.
• Citações Web of Science: 0

Resumo

Obstructive sleep apnea patients face episodes of chronic intermittent hypoxia (CIH), which has been suggested as a causative factor for increased sympathetic activity (SNA) and hypertension. Female rats exposed to CIH develop hypertension and exhibit changes in respiratory-sympathetic coupling, marked by an increase in the inspiratory modulation of SNA. We tested the hypothesis that enhanced inspiratory-modulation of SNA is dependent on carotid bodies (CBs) and are associated with changes in respiratory network activity. For this, in CIH-female rats we evaluated the effect of CBs ablation on respiratory-sympathetic coupling, recorded from respiratory neurons in the working heart-brainstem preparation and from NTS neurons in brainstem slices. CIH-female rats had an increase in peripheral chemoreflex response and in spontaneous excitatory neurotransmission in NTS. CBs ablation prevents the increase in inspiratory modulation of SNA in CIH-female rats. Pre-inspiratory/inspiratory (Pre-I/I) neurons of CIH-female rats have a reduced firing frequency. Post-inspiratory neurons are active for a longer period during expiration in CIH-female rats. Further, using the computational model of a brainstem respiratory-sympathetic network, we demonstrate that a reduction in Pre-I/I neuron firing frequency simulates the enhanced inspiratory SNA modulation in CIH-female rats. We conclude that changes in respiratory-sympathetic coupling in CIH-female rats is dependent on CBs and it is associated with changes in firing properties of specific respiratory neurons types. (C) 2019 IBRO. Published by Elsevier Ltd. All rights reserved. (AU)

• Processo FAPESP: 13/06077-5 - Alterações nas redes neurais envolvidas na geração e controle das atividades simpática e respiratória em diferentes modelos experimentais de hipóxia
• Beneficiário: Benedito Honorio Machado
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 15/06550-8 - Mecanismos neurais envolvidos na geração da hipertensão arterial em ratas submetidas à hipóxia crônica intermitente
• Beneficiário: George Miguel Perbone Robuste Souza
• Modalidade de apoio: Bolsas no Brasil - Doutorado