In this study, in vitro intact hippocampal preparation model was utilized to observe the
effects of propofol and ketamine on the neural oscillations in CA1 of rat hippocampus.
The intact hippocampi were dissected from the brain tissues of rats aged 14-16 days
postnatal. Local field potential (LFP) recordings were performed with propofol and
ketamine bath application at different concentrations. The power spectrum intensity of
LFP in all the frequency bands, including delta (1-4 Hz), theta (4-8 Hz), alpha (8-13
Hz), beta (13-30 Hz) and gamma (30-80 Hz), were inhibited in a concentration
dependent manner by both general anesthetics. In order to further investigate the
underlying mechanisms, the major binding site of propofol and ketamine were blocked
respectively by picrotoxin and (2R)-amino-5-phosphonopentanoate when bath
applying the general anesthetics. It revealed that the inhibitory effect of propofol on
hippocampal oscillations might be via γ-aminobutyric acid A receptor, while the
inhibitory effect of ketamine might be unconcerned with N-methyl-D-aspartic acid
receptor.