title: Effects of felbamate, gabapentin and lamotrigine on seizure parameters and excitability in the rat hippocampus.
abstract: The effects of three new antiepileptic drugs (felbamate, lamotrigine and gabapentin) on the parameters of seizure initiation and termination in one model of reverberatory seizures in the hippocampal-parahippocampal loop in urethane-anesthetized rats were determined. All three of the drugs caused a dose-dependent decrease in the duration of the seizure discharge. Only very high doses of felbamate had a significant effect on seizure initiation. In addition to the seizure model, we tested the three new anti-epileptic drugs for an effect on excitability, on paired-pulse inhibition and on long-term potentiation (LTP) in the dentate gyrus of the urethane-anesthetized rat. None of the drugs altered LTP or excitability. However, gabapentin altered paired-pulse inhibition, causing a loss of inhibition. For felbamate and lamotrigine, the effects of seizure duration are consistent with their clinical effects as antiepileptic drugs. However, the effect of gabapentin on paired-pulse inhibition suggests a proconvulsant effect and the effect on seizure duration suggests an antiepileptic effect.
authors.affiliation: Department of Pharmacology, Baylor College of Medicine, Houston, TX 77030, USA.
authors.forename: Z Q
authors.initials: ZQ
authors.lastname: Xiong
authors.forename: J L
authors.initials: JL
authors.lastname: Stringer
mesh_terms: D000085:Acetates / Q000494:pharmacology; D000588:Amines; D000818:Animals; D000927:Anticonvulsants / Q000494:pharmacology*; D003509:Cyclohexanecarboxylic Acids; D004305:Dose-Response Relationship, Drug; D005071:Evoked Potentials / Q000187:drug effects*; D000078328:Felbamate; D000077206:Gabapentin; D006624:Hippocampus / Q000187:drug effects*; D000077213:Lamotrigine; D008297:Male; D048448:Phenylcarbamates; D011409:Propylene Glycols / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D012640:Seizures / Q000188:drug therapy; D014227:Triazines / Q000494:pharmacology; D005680:gamma-Aminobutyric Acid
chemical_list: D000085:Acetates; D000588:Amines; D000927:Anticonvulsants; D003509:Cyclohexanecarboxylic Acids; D048448:Phenylcarbamates; D011409:Propylene Glycols; D014227:Triazines; D005680:gamma-Aminobutyric Acid; D000077206:Gabapentin; D000077213:Lamotrigine; D000078328:Felbamate