TY - JOUR
T1 - Propofol inhibits long-term potentiation but not long-term depression in rat hippocampal slices
AU - Nagashima, Kimimoto
AU - Zorumski, Charles F.
AU - Izumi, Yukitoshi
PY - 2005/8
Y1 - 2005/8
N2 - Background: Although propofol is known to produce amnesia when used for anesthesia, mechanisms underlying its effects on memory are poorly understood. The current study was designed to examine the effects of propofol on forms of synaptic plasticity thought to contribute to memory processing. Methods: Extracellular excitatory postsynaptic potentials were recorded from the CA1 region of rat hippocampal slices. Long-term potentiation (LTP) was induced using θ-burst stimulation (10 bursts of 4 pulses at 100 Hz, applied at 5 Hz) of the Schaffer-collateral pathway, while low-frequency stimulation (1 Hz × 900 pulses) was delivered to induce long-term depression. The authors also used higher-frequency stimulation (10 bursts of 4 pulses at 200 Hz, applied at 5 Hz) in the presence of MK-801 to examine the effects of propofol on an N-methyl-D-aspartate receptor-independent form of LTP. Results: At 30 μM, propofol inhibited LTP induction produced by θ-burst stimulation but had less effect on LTP maintenance. Similarly, when LTP was induced by 200-Hz stimulation in the presence of MK-801, propofol also blocked LTP induction. Propofol did not block LTP induction in the presence of picrotoxin, a specific antagonist of γ-aminobutyric acid type A receptors, suggesting that modulation of γ-aminobutyric acid type A receptors participates in propofol-mediated LTP inhibition. Propofol did not inhibit long-term depression. Conclusions: Propofol inhibits LTP induction through modulation of γ-aminobutyric acid type A receptors but not via inhibition of N-methyl-D-aspartate receptors. However, other factors also possibly contribute to propofol-mediated LTP inhibition.
AB - Background: Although propofol is known to produce amnesia when used for anesthesia, mechanisms underlying its effects on memory are poorly understood. The current study was designed to examine the effects of propofol on forms of synaptic plasticity thought to contribute to memory processing. Methods: Extracellular excitatory postsynaptic potentials were recorded from the CA1 region of rat hippocampal slices. Long-term potentiation (LTP) was induced using θ-burst stimulation (10 bursts of 4 pulses at 100 Hz, applied at 5 Hz) of the Schaffer-collateral pathway, while low-frequency stimulation (1 Hz × 900 pulses) was delivered to induce long-term depression. The authors also used higher-frequency stimulation (10 bursts of 4 pulses at 200 Hz, applied at 5 Hz) in the presence of MK-801 to examine the effects of propofol on an N-methyl-D-aspartate receptor-independent form of LTP. Results: At 30 μM, propofol inhibited LTP induction produced by θ-burst stimulation but had less effect on LTP maintenance. Similarly, when LTP was induced by 200-Hz stimulation in the presence of MK-801, propofol also blocked LTP induction. Propofol did not block LTP induction in the presence of picrotoxin, a specific antagonist of γ-aminobutyric acid type A receptors, suggesting that modulation of γ-aminobutyric acid type A receptors participates in propofol-mediated LTP inhibition. Propofol did not inhibit long-term depression. Conclusions: Propofol inhibits LTP induction through modulation of γ-aminobutyric acid type A receptors but not via inhibition of N-methyl-D-aspartate receptors. However, other factors also possibly contribute to propofol-mediated LTP inhibition.
UR - http://www.scopus.com/inward/record.url?scp=23044460434&partnerID=8YFLogxK
U2 - 10.1097/00000542-200508000-00015
DO - 10.1097/00000542-200508000-00015
M3 - Article
C2 - 16052114
AN - SCOPUS:23044460434
SN - 0003-3022
VL - 103
SP - 318
EP - 326
JO - Anesthesiology
JF - Anesthesiology
IS - 2
ER -