Effects of Propofol and Ketamine on The Neural Oscillations in CA1 of Rat Intact Hippocampus

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 concentrationdependent 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.