Research Project
Grant-in-Aid for Scientific Research (B)
We analyze the in vivo and in vitro phenotype of mice lacking the GABA_<B1> gene specifically in orexin neurons (GABA_<B1>^<flox/flox> ; orexin-Cre mice), and demonstrate that GABA_B receptors on orexin neurons are essential in stabilizing and consolidating sleep/wake states. In GABA_<B1>^<flox/flox> ; orexin-Cre brain slices, we show that the absence of GABA_B receptors decreases the sensitivity of orexin neurons to both excitatory and inhibitory inputs, due to an augmented GABA_A-mediated inhibition that increases the membrane conductance and shunts postsynaptic currents in these neurons. This increase in GABA_A-mediated inhibitory tone is apparently due to an OX1 orexin receptor-mediated activation of local GABAergic interneurons that project back onto orexin neurons. GABA_<B1>^<flox/flox> ; orexin-Cre mice exhibit severe fragmentation of sleep/wake states during both the light and dark periods, without showing an abnormality in total sleep time or signs of cataplexy. Thus, GABA_B receptors on orexin neurons are crucial in the appropriate control of the orexinergic tone through sleep/wake states, thereby stabilizing the state switching mechanisms. We also made mice lacking the 5HT1a gene specifically in orexin neurons, and are anlyzing their phenotypes.
All 2010 2009 2008 2007
All Journal Article (26 results) (of which Peer Reviewed: 26 results) Presentation (22 results) Book (2 results)
J.Mol.Neurosci. (印刷中)
Biomed Res. 30
Pages: 357-364
Cell Metab. 10
Pages: 466-480
Brain Res 1262
Pages: 25-37
J.Neurosci. 29
Pages: 3705-3714
Proc.Natl.Acad.,Sci.,USA. 106
Pages: 3930-3934
Pages: 4459-64
PLoS ONE. 4
Cell Metab. 9
Pages: 64-76
Cell Metab 10
Acta Physiol(Oxf) (印刷中)
J. Neurosci 29
Proc. Natl. Acad., Sci, USA 106
Pages: 4459-4464
Cell Metab 9
Results Probl Cell Differ 46
Pages: 239-256
Regul Pept. 151
Pages: 147-152
Proc.Natl.Acad.,Sci.,USA. 105
Pages: 10227-10232
J Clin Invest. 118
Pages: 2471-81
J Neurosci. 28
Pages: 228-238
J.Pharmacol.Sci. 106
Pages: 485-91
Diabetologia 51
Pages: 657-667
J. Pharmacol. Sci. 106
Pages: 485-491
Naunyn Schmiedebergs Arch Pharmacol. 375
Pages: 293-301
Oocytes. Pharmacology 79
Pages: 236-242
J Physiol. 581
Pages: 649-663