Only some anticonvulsants protect against seizures induced by aminophylline in quinolone-treated genetically epilepsy prone rats

Genetically epilepsy-prone rats (GEPRs) and DBA/2 mice: Two animal models of audiogenic reflex epilepsy for the evaluation of new generation AEDs

This review summarizes the current knowledge about DBA/2 mice and genetically epilepsy-prone rats (GEPRs) and discusses the contribution of such animal models on the investigation of possible new therapeutic targets and new anticonvulsant compounds for the treatment of epilepsy. Also, possible chemical or physical agents acting as proconvulsant agents are described. Abnormal activities of enzymes involved in catecholamine and serotonin synthesis and metabolism were reported in these models, and as a result of all these abnormalities, seizure susceptibility in both animals is greatly affected by pharmacological manipulations of the brain levels of monoamines and, prevalently, serotonin. In addition, both genetic epileptic models permit the evaluation of pharmacodynamic and pharmacokinetic interactions among several drugs measuring plasma and/or brain level of each compound. Audiogenic models of epilepsy have been used not only for reflex epilepsy studies, but also as animal models of epileptogenesis. The seizure predisposition (epileptiform response to sound stimulation) and substantial characterization of behavioral, cellular, and molecular alterations in both acute and chronic (kindling) protocols potentiate the usefulness of these models in elucidating ictogenesis, epileptogenesis, and their mechanisms. This article is part of a Special Issue entitled "Genetic and Reflex Epilepsies, Audiogenic Seizures and Strains: From Experimental Models to the Clinic".

A patch clamp study of the effects of ciprofloxacin and biphenyl acetic acid on rat hippocampal neurone GABAA and ionotropic glutamate receptors

The neurotoxic effects of 4-quinolones alone and in combination with certain non-steroidal anti-inflammatory drugs (NSAIDs) may be related to an interaction at GABAA and/or ionotropic glutamate receptors. In the present study, the effects of the fluoroquinolone, ciprofloxacin, alone and in combination with the NSAID, biphenyl acetic acid (BPAA), were examined on GABAA-, NMDA-, AMPA-, and kainate-evoked current responses recorded from cultured rat hippocampal neurones, using the whole cell patch clamp technique. GABA-evoked currents were reversibly inhibited by bicuculline (3 microM) and ciprofloxacin (100 microM) to 11 +/- 5 and 38 +/- 7% of control, respectively. BPAA (100 microM) had little affect on the GABA current (the response was 82 +/- 4% of control) but enhanced the inhibitory potency of ciprofloxacin by approx. 3000-fold. The antagonist effects of ciprofloxacin (30 microM) and ciprofloxacin (0.03 microM) together with BPAA (100 microM) on the GABA-evoked current were not voltage-dependent. Whole cell currents evoked by NMDA, AMPA or kainate were little influenced by ciprofloxacin (100 microM), BPAA (100 microM), or ciprofloxacin plus BPAA (both at 100 microM); the responses being > or = 90% of control in all cases. These data suggest that the proconvulsant effects of quinolones when combined with BPAA may be related to antagonism of central GABAA receptors but not to an interaction at ionotropic glutamate receptors.