title: Chronic application of topiramate and carbamazepine differentially affects the EEG and penicillin-induced epileptiform activity in rats.
abstract: Carbamazepine (CBZ) and topiramate (TPM) are among commonly used antiepileptic drugs. The acute actions of these drugs are well known but the effects of long-term use on partially induced epileptiform characteristics are yet to be clarified. The rats were received  CBZ (154 mg/kg/day), TPM (10 mg/kg/day) or tap water by gavage. We investigated penicillin-induced cortical epileptiform activity and electroencephalogram spectral power of rats by using electrocorticogram recordings. Animals were anesthetized with i.p. urethane (1·25 g/kg). Analysis  of electroencephalogram recordings prior to epileptiform activity revealed that 3-week treatment of CBZ significantly increased relative power of delta (P<0·01) while reduced alpha (P<0·017) and beta (P<0·017) relative power compared to both  control group and TPM group. TPM had no effect on absolute power and relative power of any frequency band. TPM treatment of 21 days significantly reduced the spike frequency (P<0·01). This preventive effect was missing in CBZ-treated rats. Upon the application of the last  dose of drugs during ongoing epileptiform activity, the drugs suppressed the epileptiform activity. However, TPM was more rapid and effective than CBZ. In conclusion, our in vivo electrophysiological data suggest that TPM is more effective in animal model of partial epilepsy at the  applied doses in this study.
authors.affiliation: Department of Biophysics, Karadeniz Technical University, Trabzon, Turkey.
authors.forename: Selcen
authors.initials: S
authors.lastname: Aydin-Abidin
authors.forename: Mehmet
authors.initials: M
authors.lastname: Yildirim
authors.forename: İsmail
authors.initials: İ
authors.lastname: Abidin
authors.forename: Ali
authors.initials: A
authors.lastname: Cansu
mesh_terms: D000818:Animals; D000927:Anticonvulsants / Q000494:pharmacology*; D001921:Brain / Q000187:drug effects*; D002220:Carbamazepine / Q000494:pharmacology*; D004195:Disease Models, Animal; D004569:Electroencephalography / Q000187:drug effects; D004828:Epilepsies, Partial / Q000188:drug therapy*; D005260:Female; D005632:Fructose / Q000031:analogs & derivatives* / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D000077236:Topiramate
chemical_list: D000927:Anticonvulsants; D000077236:Topiramate; D005632:Fructose; D002220:Carbamazepine