Dr. Yasumasa Okada

Dr. Yasumasa Okada

Division of Internal Medicine and Laboratory of Electrophysiology

Murayama Medical Center, Japan

Associate Professor



1987 Ph.D.,Keio University, Japan

1983 M.Sc., Keio University, Japan

1979 B.Sc., Keio University, Japan


  1. Lal A, Oku Y, Hülsmann S, Okada Y, Miwakeichi F, Kawai S, Tamura Y, Ishiguro M (2011) Dual oscillator model of the respiratory neuronal network generating quantal slowing of respiratory rhythm. Journal of Computational Neuroscience 30(2): 225-240.
  2. Miwakeichi F, Oku Y, Okada Y, Kawai S, Tamura Y, Ishiguro M (2011) Detection and visualization method of dynamic state transition for biological spatio-temporal imaging data. IEEE Transactions on Medical Imaging (IEEE Trans Med Imaging) 30(3): 859-866.
  3. Koganezawa T, Okada Y, Terui N, Paton JFR, Oku Y (2011) Aμ-opioid receptor agonist DAMGO induces rapid breathing in the arterially-perfused in situ preparation of rat. Respiratory Physiology and Neurobiology 177:207-211.
  4. Aoyama R, Okada Y, Yokota S, Yasui Y, Fukuda K, Shinozaki Y, Yoshida H, Nakamura M, Chiba K, Yasui Y, Kato F, Toyama Y (2011) Spatiotemporal and anatomical analyses of P2X receptor-mediated neuronal and glial processing of sensory signals in the rat dorsal horn. Pain 152: 2085-2097 [Epub ahead of print, June 11, 2011]
  5. Ishiguro M, Kawai S, Okada Y, Oku Y, Miwakeichi F, Tamura Y, Lal A (2010) What does the multi-peaked respiratory output pattern tell us about the respiratory pattern generating neuronal network? Advances in Experimental Medicine and Biology 669: 235-238.
  6. Yokota S, Shinozaki Y, Oku Y,Okada Y, Yasui Y (2010) Vesicular glutamate transporter 2-immunoreactive synapses onto phrenic motoneurons in the neonatal rat. Advances in Experimental Medicine and Biology 669: 189-192.
  7. Masumiya H, Oku Y, Okada Y (2009).Inhomogeneous distribution of action potential characteristics in the rabbit sino-atrial node revealed by voltage imaging. Journal of Physiological Sciences 59: 227-241.
  8. Kawai S, Oku Y, Okada Y, Miwakeichi F, Tamura Y, Ishiguro M (2009). A novel statistical analysis of voltage-imaging data by structural time series modeling and its application to the respiratory neuronal network. Neuroscience Research 63(3):165-171.
  9. Okada Y, Yokota S, Shinozaki Y, Aoyama R, Yasui Y, Ishiguro M, Oku Y (2009).Anatomical architecture and responses to acidosis of a novel respiratory neuron group in the high cervical spinal cord (HCRG) of the neonatal rat. Advances in Experimental Medicine and Biology 648: 387-394.
  10. Oku Y, Kimura N, Masumiya H, Okada Y (2008).Spatiotemporal organization of frog respiratory neurons visualized on the ventral medullary surface. Respiratory Physiology and Neurobiology 161: 281-290.
  11. Aoki T, Yamasawa F, Kawashiro T, Shibata T, Ishizaka A, Urano T, Okada Y (2008).Effects of long-term low-dose oxygen supplementation on the epithelial function, collagen metabolism and interstitial fibrogenesis in the guinea pig lung. Respiratory Research 9:37 (e-publish only).
  12. Oyamada Y, Murai M, Harada N, Ishizaka A, Okada Y (2008).Age-dependent involvement of ATP-sensitive potassium channel Kir6.2 in hypoxic ventilatory depression of mouse. Respiratory Physiology and Neurobiology 162: 80-84.
  13. Oku Y, Okabe A, Hayakawa T, Okada Y (2008).Respiratory neuron group in the high cervical spinal cord discovered by optical imaging. Neuroreport 19(17): 1739-1743.
  14. Nishii Y, Okada Y, Yokoba M, Katagiri M, Yanaihara T, Masuda N, Easton PA, Abe T (2008). Aminophylline increases parasternal intercostal muscle activity during hypoxia in humans. Respiratory Physiology and Neurobiology 161: 69-75.
  15. Tsujita M, Sakuraba S, Kuribayashi J, Hosokawa Y, Hatori E, Okada Y, Kashiwagi M, Takeda J, Kuwana S (2008). Antagonism of morphine-induced central respiratory depression by donepezil in anesthetized rabbit. Biological Research 40: 339-346.
  16. Umeda A, Kawasaki K, Abe T, Watanabe M, Ishizaka A, Okada Y (2008). Hyperventilation and finger exercise increase venous-arterial PCO2 and pH differences. American Journal of Emergency Medicine 26: 975-980.
  17. Okada Y, Masumiya H, Tamura Y, Oku Y (2007).Respiratory and metabolic acidosis differentially affect the respiratory neuronal network in the ventral medulla of neonatal rats. European Journal of Neuroscience 26: 2834-2843.
  18. Okada Y, Kuwana S, Masumiya H, Kimura N, Chen Z, Oku Y (2007). Chemosensitive neuronal network organization in the ventral medulla analyzed by dynamic voltage-imaging. Advances in Experimental Medicine and Biology 605: 353-358.
  19. Oku Y, Masumiya H, Okada Y (2007).Postnatal developmental changes in activation profiles of the respiratory neuronal network in the rat ventral medulla. Journal of Physiology 585(1):175-186.
  20. Fukuda K, Okada Y, Yoshida H, Aoyama R, Nakamura M, Chiba K, Toyama Y (2006). Ischemia-induced disturbance of neural network function in the rat spinal cord analyzed by voltage-imaging. Neuroscience 140(4): 1453-1465.
  21. Kuwana S, Tsunekawa N, Yanagawa Y, Okada Y, Kuribayashi J, Obata K (2006). Electrophysiological and morphological characteristics of GABAergic respiratory neurons in the mouse pre-Bötzinger complex. European Journal of Neuroscience 23(3): 667-674.
  22. Sakuraba S, Kuwana S, Eriksson LI, Okada Y, Ochiai R, Kashiwagi M, Hatori E, Lindahl SGE, Takeda J (2005). Effects of neuromuscular blocking agents on central respiratory chemosensitivity in newborn rats. Biological Research 38(2-3): 225-233.
  23. Okada Y, Kuwana S, Kawai A, Mückenhoff K, Scheid P (2005). Significance of extracellular potassium in central respiratory control studied in the isolated brainstem-spinal cord preparation of the neonatal rat. Respiratory Physiology and Neurobiology 146(1): 21-32.