Serotonergic neurons in the nucleus raphe obscurus contribute to interaction between central and peripheral ventilatory responses to hypercapnia

Autor(es)

da Silva, Glauber S. F. ^[1] ; Giusti, Humberto ^[1] ; Benedetti, Mauricio ^[1] ; Dias, Mirela B. ^[2] ; Gargaglioni, Luciane H. ^[3] ; Branco, Luiz Guilherme S. ^[4] ; Glass, Mogens L. ^[1]

Afiliação do(s) autor(es)

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

^[2] Univ Fed Goias, Inst Biol Sci, Dept Physiol Sci, Goiania, Go - Brazil

^[3] Sao Paulo State Univ UNESP FCAV Jaboticabal, Dept Anim Morphol & Physiol, Jaboticabal, SP - Brazil

^[4] Univ Sao Paulo USP FORP, Dept Morphol Stomatol & Physiol, Ribeirao Preto, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: PFLUGERS ARCHIV-EUROPEAN JOURNAL OF PHYSIOLOGY; v. 462, n. 3, p. 407-418, SEP 2011.
• Citações Web of Science: 30

Resumo

Serotonergic (5-HT) neurons in the nucleus raphe obscurus (ROb) are involved in the respiratory control network. However, it is not known whether ROb 5-HT neurons play a role in the functional interdependence between central and peripheral chemoreceptors. Therefore, we investigated the role of ROb 5-HT neurons in the ventilatory responses to CO(2) and their putative involvement in the central-peripheral CO(2) chemoreceptor interaction in unanaesthetised rats. We used a chemical lesion specific for 5-HT neurons (anti-SERT-SAP) of the ROb in animals with the carotid body (CB) intact or removed (CBR). Pulmonary ventilation (V (E)), body temperature and the arterial blood gases were measured before, during and after a hypercapnic challenge (7% CO(2)). The lesion of ROb 5-HT neurons alone (CB intact) or the lesion of 5-HT neurons of ROb+CBR did not affect baseline V (E) during normocapnic condition. Killing ROb 5-HT neurons (CB intact) significantly decreased the ventilatory response to hypercapnia (p < 0.05). The reduction in CO(2) sensitivity was approximately 15%. When ROb 5-HT neurons lesion was combined with CBR (anti-SERT-SAP+CBR), the V (E) response to hypercapnia was further decreased (-31.2%) compared to the control group. The attenuation of CO(2) sensitivity was approximately 30%, and it was more pronounced than the sum of the individual effects of central (ROb lesion; -12.3%) or peripheral (CBR; -5.5%) treatments. Our data indicate that ROb 5-HT neurons play an important role in the CO(2) drive to breathing and may act as an important element in the central-peripheral chemoreception interaction to CO(2) responsiveness. (AU)

• Processo FAPESP: 06/60696-5 - Papel do núcleo obscuro da rafe na quimiossensibilidade ao CO2/pH
• Beneficiário: Glauber dos Santos Ferreira da Silva
• Modalidade de apoio: Bolsas no Brasil - Doutorado
• Processo FAPESP: 07/51581-2 - Papel do núcleo obscuro da rafe na quimiossensibilidade ao CO2/pH
• Beneficiário: Mogens Lesner Glass
• Modalidade de apoio: Auxílio à Pesquisa - Regular