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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

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

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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]
Total Authors: 7
[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
Total Affiliations: 4
Document type: Journal article
Source: PFLUGERS ARCHIV-EUROPEAN JOURNAL OF PHYSIOLOGY; v. 462, n. 3, p. 407-418, SEP 2011.
Web of Science Citations: 30

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)