Effects of Various Antiepileptics on Behavioral and Electroencephalographic Seizures Induced by Maximal Electroshock in Mice

Abstract

Abstract. The changes of electroencephalogram induced by maximal electroshock were studied in comparison with behavioral seizures in mice. After electroshock, mice showed tonic flexor (TF) seizure, tonic extensor (TE) seizure, and clonic (CL) seizure, in this order of occurrence. At the same time, high frequency spike or spike and wave complex in the cortex was observed, and thereafter, the frequency of the spike or spike and wave complex gradually fell. The antiepileptics used in the present study, except for ethosuximide, caused a dose-dependent shortening of the TE seizure duration. In addition, phenobarbital and carbamazepine at relatively high doses also showed a significant shortening of the duration of CL seizure. Although the duration of total electroencephalographic (EEG) seizures was not influenced by all the antiepileptics used in the present study, the duration of high frequency spike or spike and wave complex observed for 7 -8 s after electroshock was dose-dependently shortened by all the antiepileptics used. From these findings, it may be concluded that high frequency spike or spike and wave complex induced by maximal electroshock is a useful index to assess antiepileptics that are effective in not only tonic-clonic seizures but also absence seizures in humans.

Participation of metabotropic glutamate receptors in pentetrazol-induced kindled seizure

“…Under pentobarbital anesthesia (60 mg/kg, i.p., Nembutal; Abbot Laboratories, North Chicago, IL, U.S.A.), the mice were fixed to a stereotaxic apparatus (SR‐5; Narishige, Tokyo, Japan). According to the atlas of Franklin and Paxinos (1996), monopolar screw electrodes were implanted in the right frontal cortex (FCOR, A: +3.0, L: +1.0), left occipital cortex (L‐OCOR, A: −4.3, L: −2.4), and right occipital cortex (R‐OCOR, A: −4.3, L: +2.4) (Murakami et al., 2008). A reference electrode was implanted in the occipital part of the cranium.…”

Effects of Antiepileptics on Behavioral and Electroencephalographic Seizure Induced by Pentetrazol in Mice

“…On the other hand, PTZ-induced seizure shows fast trains of spike discharges and subsequently a slow wave appears on the EEG (14,15). We have reported that EEG changes induced by maximal electroshock were a useful index to assess the potential of antiepileptic activity (16); however, there is little information about the detailed EEG changes induced by PTZ administration in animals, except for a few papers. It is presumed that the measurement of EEG changes will provide new information that cannot be obtained with only behavior observation; therefore, we measured EEG changes as well as seizure symptoms induced by PTZ in detail.…”