Carbamazepine-induced blockade of induction of long-term potentiation in the perforant path-dentate gyrus pathway in chronically prepared rabbits

Abstract

We investigated the effects of a representative anti-epileptic or anti-psychotic drug, carbamazepine (CBZ), on the induction of long-term potentiation (LTP) in the perforant path-dentate gyrus pathway in 15 chronically prepared rabbits. Pharmacokinetically injected low-dose CBZ, which produced steady serum levels of 2.2–3.3 μg/ml (mean ± S.D. 2.85 ± 0.40), variably affected the induction of LTP, blocking it or showing almost no effect. The high-dose CBZ, which produced steady serum levels of 6.5–8.6 μg/ml (8.01 ± 0.87), always blocked the induction of LTP. These results indicate that CBZ dose-dependently blocks the induction of LTP. The possible mechanisms underlying this blockade are discussed, especially in association with the possible inhibitory action of CBZ on N- methyl- d-aspartate (NMDA) receptors.