TY - JOUR
T1 - The sensitivity of hyperpolarization-activated cation current (I h) to propofol in rat area postrema neurons
AU - Funahashi, Makoto
AU - Mitoh, Yoshihiro
AU - Matsuo, Ryuji
N1 - Funding Information:
We thank Dr. Mark Stewart (SUNY Downstate Medical Center, Brooklyn, NY) for his helpful comments on the manuscript. This research was supported by grants from the Ministry of Education, Science and Culture of Japan, Kato Memorial Foundation, Kobayashi Magobei Memorial Foundation and Novartis Foundation (Japan) for the Promotion of Science.
PY - 2004/7/23
Y1 - 2004/7/23
N2 - Area postrema neurons mediate various autonomic responses, including emesis. We examined the effects of propofol, a widely used anesthetic with antiemetic properties, on the hyperpolarization-activated cation current (I h) in rat area postrema neurons using a slice patch-clamp technique. Although propofol suppressed Ih of area postrema neurons in a dose-dependent manner that was similar to what we observed for the hippocampal CA1 neurons, the IC50 for Ih in area postrema neurons (38 μM) was more than six times less than that found for hippocampal CA1 neurons (235 μM). We conclude that rat area postrema neurons are exquisitely sensitive to propofol. Given that reductions of Ih are associated with decreased excitability in neurons, we believe that the known antiemetic effects of propofol anesthesia are at least partly a result of a direct action on area postrema neurons to lower their excitability.
AB - Area postrema neurons mediate various autonomic responses, including emesis. We examined the effects of propofol, a widely used anesthetic with antiemetic properties, on the hyperpolarization-activated cation current (I h) in rat area postrema neurons using a slice patch-clamp technique. Although propofol suppressed Ih of area postrema neurons in a dose-dependent manner that was similar to what we observed for the hippocampal CA1 neurons, the IC50 for Ih in area postrema neurons (38 μM) was more than six times less than that found for hippocampal CA1 neurons (235 μM). We conclude that rat area postrema neurons are exquisitely sensitive to propofol. Given that reductions of Ih are associated with decreased excitability in neurons, we believe that the known antiemetic effects of propofol anesthesia are at least partly a result of a direct action on area postrema neurons to lower their excitability.
KW - Area postrema neuron
KW - CA1 neuron
KW - Excitable membranes and synaptic transmission
KW - Hyperpolarization-activated cation current
KW - Other ion channels
KW - Propofol
KW - Rat
KW - Slice
KW - Whole-cell patch-clamp
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U2 - 10.1016/j.brainres.2004.04.043
DO - 10.1016/j.brainres.2004.04.043
M3 - Article
C2 - 15223387
AN - SCOPUS:3042615422
SN - 0006-8993
VL - 1015
SP - 198
EP - 201
JO - Molecular Brain Research
JF - Molecular Brain Research
IS - 1-2
ER -