Blockade of 5-Ht₃ receptors in the septal area increases Fos expression in selected brain areas

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• 作者：Lilia S. Urzedo-Rodrigues ; Hilda S. Ferreira ; Rejane Concei莽茫o Santana ; Carla Patr铆cia Luz ; Camila F. Perrone ; Josmara B. Fregoneze
• 关键词：5-HT3 receptor ; Ondansetron ; c-Fos ; Septal area ; Barodenervation
• 刊名：Autonomic Neuroscience
• 出版年：April, 2014
• 年：2014
• 卷：181
• 期：Complete
• 页码：55-68
• 全文大小：3060 K

文摘

Serotonin is widely distributed throughout the brain and is involved in a multiplicity of visceral, cognitive and behavioral responses. It has been previously shown that injections of different doses of ondansetron, a 5-HT₃ receptor antagonist, into the medial septum/vertical limb of the diagonal band complex (MS/vDB) induce a hypertensive response in rats. On the other hand, administration of m-CPBG, a 5-HT₃ agonist, into the MS/vDB inhibits the increase of blood pressure during restraint stress. However, it is unclear which neuronal circuitry is involved in these responses. The present study investigated Fos immunoreactive nuclei (Fos-IR) in different brain areas following the blockade of 5-HT₃ receptors located in the MS/vDB in sham and in sinoaortic denervated (SAD) rats. Ondansetron injection into the MS/vDB increases Fos-IR in different brain areas including the limbic system (central amygdala and ventral part of the bed nucleus of the stria terminalis), hypothalamus (medial parvocellular parts of the paraventricular nucleus, anterodorsal preoptic area, dorsomedial hypothalamic nucleus), mesencephalon (ventrolateral periaqueductal gray region) and rhombencephalon (lateral parabrachial nucleus) in sham rats. Barodenervation results in higher Fos expression at the parvocellular and magnocellular part of the paraventricular nucleus, the lateral parabrachial nucleus, the central nucleus of amygdala, the locus coeruleus, the medial part of the nucleus of the solitary tract, the rostral ventrolateral medulla and the caudal ventrolateral medulla following 5-HT₃receptor blockade in the MS/vDB. Based on the present results and previous data showing a hypertensive response to ondansetron injected into the MS/vDB, it is reasonable to suggest that 5-HT₃receptors in the MS/vDB exert an inhibitory drive that may oscillate as a functional regulatory part of the complex central neuronal network participating in the control of blood pressure.