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CO2-sensitivity of GABAergic Neurons in the Ventral Medullary Surface of GAD67-GFP Knock-in Neonatal Mice

  • Junya Kuribayashi
  • Shigeki Sakuraba
  • Yuki Hosokawa
  • Eiki Hatori
  • Miki Tsujita
  • Junzo Takeda
  • Yuchio Yanagawa
  • Kunihiko Obata
  • Shun-ichi Kuwana
Part of the Advances in Experimental Medicine and Biology book series (AEMB, volume 605)

We investigated the CO2 responsiveness of GABAergic neurons in the ventral medullary surface (VMS), a putative chemoreceptive area using a 67-kDa isoform of GABA-synthesizing enzyme (GAD67)-green fluorescence protein (GFP) knock-in neonatal mouse, in which GFP is specifically expressed in GABAergic neurons. The slice was prepared by transversely sectioning at the level of the rostral rootlet of the XII nerve and the rostral end of the inferior olive in mock cerebrospinal fluid (CSF). Each medullary slice was continuously superfused with hypocapnic CSF. GFP-positive neurons in the VMS were selected by using fluorescent optics and their membrane potentials and firing activities were analyzed with a perforated patch recording technique. Thereafter, superfusion was changed from hypocapnic to hypercapnic CSF. In 4 out of 8 GABAergic neurons in the VMS, perfusion with hypercapnic CSF induced more than a 20% decrease in the discharge frequency and hyperpolarized the neurons. The remaining 4 GFPpositive neurons were CO2-insensitive. GABAergic neurons in the VMS have chemosensitivity. Inhibition of chemosensitive GABAergic neural activity in the VMS may induce increases in respiratory output in response to hypercapnia.

Keywords

GABAergic Neuron Discharge Frequency Inferior Olive Respiratory Neuron Respiratory Output 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Copyright information

© Springer 2008

Authors and Affiliations

  • Junya Kuribayashi
    • 1
  • Shigeki Sakuraba
    • 1
  • Yuki Hosokawa
    • 1
  • Eiki Hatori
    • 1
  • Miki Tsujita
    • 1
  • Junzo Takeda
    • 1
  • Yuchio Yanagawa
    • 2
    • 3
  • Kunihiko Obata
    • 4
  • Shun-ichi Kuwana
    • 5
  1. 1.Department of AnesthesiologyKeio University School of MedicineShinjuku-ku, TokyoJapan
  2. 2.Department of Genetic and Behavioral NeuroscienceGunma University Graduate School of MedicineMaebashiJapan
  3. 3.SORSTJapan Science and Technology CorporationKawaguchiJapan
  4. 4.Neural Circuit Mechanisms Research GroupRIKEN Brain Science InstituteWakoJapan
  5. 5.Department of PhysiologyTeikyo University School of MedicineTokyoJapan

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