The Central Respiratory Chemoreceptor: Where Is It Located?–Invited Article

Abstract

We review previous reports on the localization of the central chemoreceptor focusing on our studies that used various experimental techniques including lesioning (brainstem transection and removal of pia mater), analyses of neuronal responses to CO(2) by electrophysiological and optical recording, mapping of CO(2)-excitable neurons by c-fos immunohistochemistry and local acidic stimulation. Among these experimental techniques, voltage imaging with calculation of cross correlation coefficients between the respiratory output activity and each pixel, i.e., correlation coefficient imaging technique, enabled us to effectively analyze imaging data without empirical signal processing. The reviewed studies have indicated that the most superficial layer of the rostral ventral medulla, i.e., the surface portions of the nucleus retrotrapezoideus/parafacial respiratory group, nucleus parapyramidal superficialis and nucleus raphe pallidus, is important in central chemoreception. We suggest that one of the major respiratory rhythm generators, i.e., the preBötzinger complex, is not chemosensitive in itself or rather inhibited by CO(2). Based on our detailed analysis of c-fos immunohistochemistry, we propose a cell-vessel architecture model for the central respiratory chemoreceptor. Primary chemoreceptor cells are mainly located beneath large surface vessels within the marginal glial layer of the ventral medulla, and surround fine penetrating vessels that branch from a large surface vessel. Respiratory neurons in the rostral portion of the ventral respiratory group could be intrinsically chemosensitive, but their role in chemoreception might be secondary. Definitive identification of chemosensitive sites and chemoreceptor cells needs further studies.

Degeneration of Brainstem Respiratory Neurons in Dementia with Lewy Bodies

“…Instead, studies utilizing hypercapnia-induced c-fos expression 35 and dynamic-voltage imaging 36 have demonstrated that the more superficial layers of the ventral medulla, including the RPa and arcuate nuclei, are more likely to play a primary role in central chemoreception. 37 Whether the medullary raphe nuclei function as primary chemoreceptors or upstream integrators of chemosensitive signals, these nuclei clearly play an important role in mediation of the respiratory chemoreflex. This makes these nuclei an attractive candidate as a pathophysiological substrate of the reported impairment of the ventilatory responses to hypercapnia in DLB.…”

Neurological suppression of diaphragm electromyographs in hamsters infected with West Nile virus

“…So if motor neurons in the C3–C5 were damaged or destroyed by WNV, innervation of the diaphragm would decrease. Additionally, WNV infects and causes lesions in the brain stem of human patients (Doron et al , 2003; Petropoulou et al , 2005) and other species (Cantile et al , 2001; Siddharthan et al , 2009), which contains respiratory control functions in the medulla and pons (Dubreuil et al , 2009; Okada et al , 2009; Rudzinski and Kapur, 2009). Afferent axons from the carotid and aortic bodies in the glossopharyngeal nerve contain chemoreceptor cells and vagal afferent nerves from receptors in the lung (Goehler et al , 2006; Goehler et al , 2005; Hermann and Rogers, 2009) communicate with the medulla and pons respiratory control centers to coordination inspiration and expiration.…”

Quimiossensibilidade central e ritmicidade respiratória na Doença de Parkinson.

“…Escalas: A = 1 mm (Para A-C); A1, B1, e C1 = 100 µm (Para A1-A3, B1-B3, C1-C3) (Análise de variância de duas vias seguido pelo teste de Newman-Keuls). (Okada et al, 2009;Ribas-Salgueiro et al, 2005; (Loeschcke, 1982;Takakura et al, 2006). A quimiorrecepção central é um mecanismo pelo qual grupamentos neurais altamente especializados detectam alterações na pressão parcial de CO2 e pH e promovem alterações respiratórias com o intuito de regular a homeostase do organismo (Guyenet et al, 2008).…”