The effect of repeated ketamine administration on long-term potential in area CA1 of hippocampus in rats / 中华麻醉学杂志

ABSTRACT

Objective To investigate the effect of repeated ketamine administration on long-term potential ( LTP) in area CA1 of hippocampus. Methods Thirty SD rats of either sex aged 35-45 days were randomly divided into 2 control groups (C) and 3 ketamine groups (K). The animals in control groups received intraperitoneal (IP) normal saline (NS) 2 ml once (C1) or once every 3 days?5 times (C2); while in ketamine groups received IP ketamine 70 mg?kg-1 in 2 ml NS once (K1) or once every 3 days ?3 times (K2) or ? 5 times (K3). Seven days after the last injection the animals were killed and hippocampus slices were prepared. Electrical stimulation was delivered to the Schaffer commissural fiber system and extracellular recoding was performed at the pyramidal cell layer in hippocampal slices. LTP and population spike amplitude (PSA) after tetanus stimulation were measured and recorded.Results There was no significant difference in both PSA after tetanus stimulation and the induction ratio of LTP in area CA1 of hippocampus slices between group C1, C2 and K1. But the PSA and induction ratio of LTP were significantly decreased in group K3 as compared with group C1 and C2 ( P