H Onimaru


Affiliation: Showa University
Country: Japan


  1. request reprint
    Onimaru H, Kumagawa Y, Homma I. Respiration-related rhythmic activity in the rostral medulla of newborn rats. J Neurophysiol. 2006;96:55-61 pubmed
    ..These results show that the rostral medulla, not including the pre-Bötzinger complex, produces Pre-I-like rhythmic activity that can be monitored as facial nerve motor output in newborn rat in vitro preparations. ..
  2. Iigaya K, Minoura Y, Onimaru H, Kotani S, Izumizaki M. Effects of Feeding-Related Peptides on Neuronal Oscillation in the Ventromedial Hypothalamus. J Clin Med. 2019;8: pubmed publisher
  3. Oka A, Iizuka M, Onimaru H, Izumizaki M. Inhibitory Thoracic Interneurons are not Essential to Generate the Rostro-caudal Gradient of the Thoracic Inspiratory Motor Activity in Neonatal Rat. Neuroscience. 2019;397:1-11 pubmed publisher
  4. Ikeda K, Kaneko R, Yanagawa Y, Ogawa M, Kobayashi K, Arata S, et al. Analysis of the neuronal network of the medullary respiratory center in transgenic rats expressing archaerhodopsin-3 in Phox2b-expressing cells. Brain Res Bull. 2018;144:39-45 pubmed publisher
    ..Our findings showed that Phox2b-expressing pFRG/Pre-I neurons are involved in the maintenance of the basic respiratory rhythm in neonatal rat. ..
  5. Bautista T, Fong A, Pilowsky P, Ikeda K, Kawakami K, Spirovski D, et al. The Expression of Galanin in the Parafacial Respiratory Group and its Effects on Respiration in Neonatal Rats. Neuroscience. 2018;384:1-13 pubmed publisher
    ..Overall the peptide has an inhibitory effect on inspiratory motor output, as previously shown in adults. ..
  6. Yagura S, Onimaru H, Kanzaki K, Izumizaki M. Inhibitory effects of eugenol on putative nociceptive response in spinal cord preparation isolated from neonatal rats. Exp Brain Res. 2018;236:1767-1774 pubmed publisher
    ..Our report provides additional evidence on the basic neuronal mechanisms of eugenol to support its clinical use as a potential analgesic treatment. ..
  7. Onimaru H, Ikeda K, Kawakami K. Postsynaptic mechanisms of CO(2) responses in parafacial respiratory neurons of newborn rats. J Physiol. 2012;590:1615-24 pubmed publisher
    ..These neurons were predominantly Phox2b immunoreactive. Our findings suggest that the response of pFRG/RTN neurons to hypercapnia is induced by direct action on the postsynaptic membrane via closing of K(+) channels. ..
  8. Lin S, Onimaru H. Effects of riluzole on respiratory rhythm generation in the brainstem-spinal cord preparation from newborn rat. Neurosci Res. 2015;94:28-36 pubmed publisher
  9. Tani M, Yazawa I, Ikeda K, Kawakami K, Onimaru H. Long-lasting facilitation of respiratory rhythm by treatment with TRPA1 agonist, cinnamaldehyde. J Neurophysiol. 2015;114:989-98 pubmed publisher
    ..Our findings suggest that TRPA1 channel activation could induce long-lasting facilitation of respiratory rhythm and provide grounds for future study on the roles of TRPA1 channels in the CNS. ..

More Information


  1. Tsuzawa K, Minoura Y, Takeda S, Inagaki K, Onimaru H. Effects of α2-adorenoceptor agonist dexmedetomidine on respiratory rhythm generation of newborn rats. Neurosci Lett. 2015;597:117-20 pubmed publisher
    ..The inhibitory effect was also reversed by atipamezole. Our findings provide neuronal mechanisms that support the clinical use of dexmedetomidine, which shows sedative and antinociceptive effects with minimal side effects on breathing. ..
  2. Onimaru H, Tsuzawa K, Nakazono Y, Janczewski W. Midline section of the medulla abolishes inspiratory activity and desynchronizes pre-inspiratory neuron rhythm on both sides of the medulla in newborn rats. J Neurophysiol. 2015;113:2871-8 pubmed publisher
    ..We conclude that in newborn rats, crossed excitatory interactions (via commissural fibers) are necessary for the generation of inspiratory bursts but not for the generation of rhythmic Pre-I neuron activity. ..
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    Onimaru H, Homma I. Optical imaging of respiratory neuron activity from the dorsal view of the lower brainstem. Clin Exp Pharmacol Physiol. 2005;32:297-301 pubmed
    ..This method is very useful for analysis of pharmacological properties, as well as the spatio-temporal pattern of respiratory-related network activity in the brainstem. ..
  4. Tsuzawa K, Yazawa I, Shakuo T, Ikeda K, Kawakami K, Onimaru H. Effects of ouabain on respiratory rhythm generation in brainstem-spinal cord preparation from newborn rats and in decerebrate and arterially perfused in situ preparation from juvenile rats. Neuroscience. 2015;286:404-11 pubmed publisher
    ..We concluded that Na/K-ATPase activity could be an important factor in respiratory rhythm modulation. ..
  5. Oyama Y, Iigaya K, Minoura Y, Okabe T, Izumizaki M, Onimaru H. An in vitro experimental model for analysis of central control of sympathetic nerve activity. J Physiol Sci. 2017;67:629-635 pubmed publisher
    ..This preparation allows analysis of the central control of the SNA in vitro. ..
  6. Iigaya K, Okazaki S, Minoura Y, Onimaru H. Interaction between novel oscillation within the ventromedial hypothalamus and the sympathetic nervous system. Neuroscience. 2017;343:213-221 pubmed publisher
    ..We hypothesize that the VMH oscillation might be involved in low-frequency modulation of the SNA. ..
  7. Onimaru H, Ikeda K, Kawakami K. Phox2b expressing neurons in the most rostral medulla of newborn rats. Adv Exp Med Biol. 2010;669:87-90 pubmed publisher
    ..Here, we briefly review these recent findings. We also show a unique distribution of Phox2b expressing cells in the most rostral medulla, which could be an interesting target for neurophysiological analysis. ..
  8. Onimaru H, Ikeda K, Kawakami K. Relationship between the distribution of the paired-like homeobox gene (Phox2b) expressing cells and blood vessels in the parafacial region of the ventral medulla of neonatal rats. Neuroscience. 2012;212:131-9 pubmed publisher
    ..Our findings suggested that the location of Phox2b-ir neurons, including preinspiratory neurons of the pFRG, matched their role as sensors of blood CO(2) concentration. ..
  9. Takahashi K, Hayakawa C, Onimaru H. Effects of a quaternary lidocaine derivative, QX-314, on the respiratory activity in brainstem-spinal cord preparation from newborn rats. Neurosci Lett. 2016;619:121-5 pubmed publisher
    ..Our findings could explain one of the mechanisms underlying the central toxicities that occur after the systemic application of QX-314. ..
  10. Ikeda K, Kawakami K, Onimaru H, Okada Y, Yokota S, Koshiya N, et al. The respiratory control mechanisms in the brainstem and spinal cord: integrative views of the neuroanatomy and neurophysiology. J Physiol Sci. 2017;67:45-62 pubmed publisher
    ..In this review, we focus on the recent findings and attempt to elucidate the anatomical and functional mechanisms underlying respiratory control in the lower brainstem and spinal cord. ..
  11. Tani M, Kotani S, Hayakawa C, Lin S, Irie S, Ikeda K, et al. Effects of a TRPV1 agonist capsaicin on respiratory rhythm generation in brainstem-spinal cord preparation from newborn rats. Pflugers Arch. 2017;469:327-338 pubmed publisher
    ..Our results also suggested a minor contribution of the TRPV1 channels to central chemoreception. ..
  12. Onimaru H, Nakamura S, Ikeda K, Kawakami K, Inoue T. Confocal calcium imaging analysis of respiratory-related burst activity in the parafacial region. Brain Res Bull. 2018;139:16-20 pubmed publisher
    ..We found that more than 60% of the EYFP/Phox2b-positive cells showed Pre-I neuron-like rhythmic burst activity in the parafacial region of newborn rat. ..
  13. request reprint
    Onimaru H, Arata A, Arata S, Shirasawa S, Cleary M. In vitro visualization of respiratory neuron activity in the newborn mouse ventral medulla. Brain Res Dev Brain Res. 2004;153:275-9 pubmed
    ..Such an activity pattern was not clearly detected in Pbx3-/- mouse preparations. The difference in the spatio-temporal pattern between Tlx3-/- and Pbx3-/- suggests different levels of functional disorder of the respiratory center. ..
  14. request reprint
    Onimaru H, Homma I. Point:Counterpoint: The parafacial respiratory group (pFRG)/pre-Botzinger complex (preBotC) is the primary site of respiratory rhythm generation in the mammal. Point: the PFRG is the primary site of respiratory rhythm generation in the mammal. J Appl Physiol (1985). 2006;100:2094-5 pubmed
  15. Lin S, Ohbayashi M, Yamamoto T, Onimaru H, Kogo M. Effects of riluzole on spinal seizure-like activity in the brainstem-spinal cord preparation of newborn rat. Neurosci Res. 2017;125:46-53 pubmed publisher
    ..Riluzole at the optimal dose could be a potential treatment to protect drug-induced epileptic brain tissue from excitotoxic damage without inducing respiratory suppression. ..
  16. Kotani S, Irie S, Izumizaki M, Onimaru H. Effects of eugenol on respiratory burst generation in newborn rat brainstem-spinal cord preparations. Pflugers Arch. 2018;470:385-394 pubmed publisher
    ..These results suggest that changes in both membrane excitability and synaptic connections are involved in the shortening of respiratory neuron bursts by eugenol. ..
  17. Onimaru H, Ikeda K, Kawakami K. CO2-sensitive preinspiratory neurons of the parafacial respiratory group express Phox2b in the neonatal rat. J Neurosci. 2008;28:12845-50 pubmed publisher
    ..Our findings suggest that Phox2b-expressing parafacial neurons play a role in respiratory rhythm generation as well as central chemoreception and thus are essential for postnatal survival. ..
  18. Onimaru H, Ikeda K, Kawakami K. Defective interaction between dual oscillators for respiratory rhythm generation in Na+,K+-ATPase {alpha}2 subunit-deficient mice. J Physiol. 2007;584:271-84 pubmed
    ..Coupling was partially restored by repeated activation of the neurons within the networks, suggesting the involvement of an activity-dependent process in the prenatal development of this coupling. ..