Firing properties of ventral medullary respiratory neurons in sino-aortic denervated rats

Autor(es)

Amorim, Mateus R. ^[1] ; Pena, Rodrigo F. O. ^[2] ; Souza, George M. P. R. ^[1] ; Bonagamba, Leni G. H. ^[1] ; Roque, Antonio C. ^[2] ; Machado, Benedito H. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Sch Med Ribeirao Preto, Dept Physiol, BR-14049900 Ribeirao Preto, SP - Brazil

^[2] Univ Sao Paulo, Sch Philosophy Sci & Letters Ribeirao Preto, Dept Phys, BR-14040900 Ribeirao Preto, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Experimental Physiology; v. 104, n. 1, p. 39-49, JAN 2019.
• Citações Web of Science: 0

Resumo

In previous studies, we documented that after sino-aortic denervation (SAD) in rats there are significant changes in the breathing pattern, but no significant changes in sympathetic activity and mean arterial pressure compared with sham-operated rats. However, the neural mechanisms involved in the respiratory changes after SAD and the extent to which they might contribute to the observed normal sympathetic activity and mean arterial pressure remain unclear. Here, we hypothesized that after SAD, rats present with changes in the firing frequency of the ventral medullary inspiratory and post-inspiratory neurons. To test this hypothesis, male Wistar rats underwent SAD or sham surgery and 3 days later were surgically prepared for an in situ experiment. The duration of inspiration significantly increased in SAD rats. During inspiration, the total firing frequency of ramp-inspiratory, pre-inspiratory/inspiratory and late-inspiratory neurons was not different between groups. During post-inspiration, the total firing frequency of post-inspiratory neurons was also not different between groups. Furthermore, the data demonstrate a reduced interburst frequency of pre-inspiratory/inspiratory neurons and an increased long-term variability of late-inspiratory neurons in SAD compared with sham-operated rats. These findings indicate that the SAD-induced prolongation of inspiration was not accompanied by alterations in the total firing frequency of the ventral medullary respiratory neurons, but it was associated with changes in the long-term variability of late-inspiratory neurons. We suggest that the timing imbalance in the respiratory network in SAD rats might contribute to the modulation of presympathetic neurons after removal of baroreceptor afferents. (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: 15/50122-0 - Fenômenos dinâmicos em redes complexas: fundamentos e aplicações
• Beneficiário: Elbert Einstein Nehrer Macau
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 13/15195-1 - Caracterização eletrofisiológica dos neurônios respiratórios e pré-simpáticos da região rostral ventrolateral do bulbo após a desnervação sino-aórtica em ratos
• Beneficiário: Mateus Ramos Amorim
• Modalidade de apoio: Bolsas no Brasil - Doutorado
• Processo FAPESP: 13/07699-0 - Centro de Pesquisa, Inovação e Difusão em Neuromatemática - NeuroMat
• Beneficiário: Oswaldo Baffa Filho
• Modalidade de apoio: Auxílio à Pesquisa - Centros de Pesquisa, Inovação e Difusão - CEPIDs
• Processo FAPESP: 13/25667-8 - Mecanismos de propagação de atividade epileptiforme em um modelo cortical de grande porte
• Beneficiário: Rodrigo Felipe de Oliveira Pena
• Modalidade de apoio: Bolsas no Brasil - Doutorado Direto