Abstract
It has been postulated that there exists a neuronal mechanism that generates respiratory rhythm and modulates respiratory output pattern in the high cervical spinal cord. Recently, we have found a novel respiratory neuron group in the ventral portion of the high cervical spinal cord, and named it the high cervical spinal cord respiratory group (HCRG). In the present study, we analyzed the detailed anatomical architecture of the HCRG region by double immunostaining of the region using a neuron-specific marker (NeuN) and a marker for motoneurons (ChAT) in the neonatal rat. We found a large number of small NeuN-positive cells without ChAT-immunoreactivity, which were considered interneurons. We also found two and three clusters of motoneurons in the ventral portion of the ventral horn at C1 and C2 levels, respectively. Next, we examined responses of HCRG neurons to respiratory and metabolic acidosis in vitro by voltage-imaging together with cross correlation techniques, i.e., by correlation coefficient imaging, in order to understand the functional role of HCRG neurons. Both respiratory and metabolic acidosis caused the same pattern of changes in their spatiotemporal activation profiles, and the respiratory-related area was enlarged in the HCRG region. After acidosis was introduced, preinspiratory phase-dominant activity was recruited in a number of pixels, and more remarkably inspiratory phase-dominant activity was recruited in a large number of pixels. We suggest that the HCRG composes a local respiratory neuronal network consisting of interneurons and motoneurons and plays an important role in respiratory augmentation in response to acidosis.
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Aoki M, Mori S, Kawahara K, Watanabe H, Ebata N. Generation of spontaneous respiratory rhythm in high spinal cats. Brain Res. 1980; 202: 51–63.
Douse MA, Duffin J, Brooks D, Fedorko L. Role of upper cervical inspiratory neurons studied by cross-correlation in the cat. Exp. Brain Res. 1992; 90: 153–162.
Lipski J, Duffin J. An electrophysiological investigation of propriospinal inspiratory neurons in the upper cervical cord of the cat. Exp. Brain Res. 1986; 61: 625–637.
Lipski J, Duffin J, Kruszewska B, Zhang XM. Upper cervical inspiratory neurons in the rat: an electrophysiological and morphological study. Exp. Brain Res. 1993; 95: 477–487.
Lu F, Qin C, Foreman RD, Farber JP. Chemical activation of C1–C2 spinal neurons modulates intercostal and phrenic nerve activity in rats. Am. J. Physiol. Regul. Integr. Comp. Physiol. 2004; 286: R1069–R1076.
Miyake A, Yamada K, Kosaka T, Miki T, Seino S, Inagaki N. Disruption of Kir6.2-containing ATP-sensitive potassium channels impairs maintenance of hypoxic gasping in mice. Eur. J. Neurosci. 2007; 25: 2349–2363.
Okada Y, Masumiya H, Tamura Y, Oku Y. Respiratory and metabolic acidosis differentially affect the respiratory neuronal network in the ventral medulla of neonatal rats. Eur. J. Neurosci. 2007; 26: 2834–2843.
Oku Y, Kimura N, Masumiya H, Okada Y. Spatiotemporal organization of frog respiratory neurons visualized on the ventral medullary surface. Resp. Physiol. Neurobiol. 2008a; 161: 281–290.
Oku Y, Masumiya H, Okada Y. Postnatal developmental changes in activation profiles of the respiratory neuronal network in the rat ventral medulla. J. Physiol. 2007; 585: 175–186.
Oku Y, Okabe, Hayakawa T, Okada Y. A respiratory neuron group in the high cervical spinal cord discovered by optical imaging. Neuroreport 2008b; 161:281–290.
Smith JC, Greer JJ, Liu GS, Feldman JL. Neural mechanisms generating respiratory pattern in mammalian brain stem-spinal cord in vitro. I. Spatiotemporal patterns of motor and medullary neuron activity. J Neurophysiol. 1990; 64: 1149–1169.
Yokota S, Oka T, Tsumori T, Nakamura S, Yasui Y. Glutamatergic neurons in the Kölliker-Fuse nucleus project to the rostral ventral respiratory group and phrenic nucleus: a combined retrograde tracing and in situ hybridization study in the rat. Neurosci. Res. 2007; 59: 341–346.
Yokota S, Tsumori T, Oka T, Nakamura S, Yasui Y. GABAergic neurons in the ventrolateral subnucleus of the nucleus tractus solitarius are in contact with Kölliker-Fuse nucleus neurons projecting to the rostral ventral respiratory group and phrenic nucleus in the rat. Brain Res. 2008; 1228: 113–126.
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Okada, Y. et al. (2009). Anatomical Architecture and Responses to Acidosis of a Novel Respiratory Neuron Group in the High Cervical Spinal Cord (HCRG) of the Neonatal Rat. In: Gonzalez, C., Nurse, C.A., Peers, C. (eds) Arterial Chemoreceptors. Advances in Experimental Medicine and Biology, vol 648. Springer, Dordrecht. https://doi.org/10.1007/978-90-481-2259-2_44
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DOI: https://doi.org/10.1007/978-90-481-2259-2_44
Publisher Name: Springer, Dordrecht
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