Pavel Mares̆

An antagonist of type I metabotropic glutamate receptors MPEP was found to exhibit anticonvulsant action in adult rodents. Present experiments were focused on action of this drug against pentetrazol-induced motor seizures in immature rats 12-, 18- and 25-days old. Dose of pentetrazol (100 mg/kg s.c.) was chosen to elicit minimal clonic seizures and (after a longer latency) generalized tonic-clonic seizures. Pretreatment with MPEP (doses from 10 to 80 mg/kg i.p.) resulted in a ...

Previous studies demonstrated that selected agonists for metabotropic glutamate group II and group III receptors can provide protection against seizures in adult animals. The present study has examined the potential effect of some of these compounds on seizures induced in immature rats by intracerebroventricular infusion of DL-homocysteic acid (DL-HCA, 600 nmol/side). Rat pups were sacrificed during generalised clonic-tonic seizures, 50--60 min after infusion. Comparable time intervals ...

The present study has examined the anticonvulsant and neuroprotective effect of group II metabotropic glutamate receptor (mGluR) agonist (2R,4R)-4-aminopyrrolidine-2,4-dicarboxylate (2R,4R-APDC) in the model of seizures induced in immature 12-day-old rats by bilateral intracerebroventricular infusion of dl-homocysteic acid (DL-HCA, 600 nmol/side). For biochemical analyses, rat pups were sacrificed during generalized clonic-tonic seizures, approximately 45-50 min after infusion. ...

The present study has examined the effect of free radical spin trap N-tert-butyl-alpha-phenylnitrone (PBN) in the model of seizures induced in immature 12-day-old rats by bilateral intracerebroventricular infusion of dl-homocysteic acid (dl-HCA, 600 nmol/side). PBN was given i.p. in two doses (100 mg/kg each), 30 min prior and 30 min after dl-HCA infusion. PBN did not significantly influence the severity of seizures, evident both from the behavioral symptoms and EEG recordings. PBN ...

PURPOSE: Antagonists of group I metabotropic glutamate receptors (mGluRs) are known to exhibit anticonvulsant action without serious side effects. Recently we found anticonvulsant effects of specific antagonists of mGluR subtypes 1 and 5 (AIDA and MTEP) against pentetrazol-induced convulsions in developing rats. In order to determine if the effects of these two antagonists are not exclusively restricted to pentetrazol-induced seizures, we studied their action in a novel seizure model ...

Antagonists of type I of metabotropic glutamate receptors exhibit anticonvulsant action in adult as well as immature rodents. To know the anticonvulsant profile of a specific mGluR5 antagonist MPEP in developing rats, two models of epileptic seizures were used. MPEP (10, 20 or 40 mg/kg i.p.) suppressed in a dose-dependent manner epileptic afterdischarges induced by electrical stimulation of sensorimotor cortical area in three age groups (12, 18 and 25 days old). The anticonvulsant action ...

The potential anticonvulsant effect of group III metabotropic glutamate receptor (mGluR) agonist (R,S)-4-phosphonophenylglycine ((R,S)-PPG) against seizures induced in immature 12-day-old rats by bilateral intracerebroventricular (icv) infusion of DL-homocysteic acid (DL-HCA, 600 nmol/side) was examined in the present study. Rat pups were sacrificed during generalized clonic-tonic seizures, approximately 45 to 50 min after infusion. Comparable time intervals were used for sacrificing the ...

Glutamate is the main excitatory neurotransmitter in the brain and ionotropic glutamate receptors mediate the majority of excitatory neurotransmission (Dingeldine et al. 1999). The high level of glutamatergic excitation allows the neonatal brain (the 2(nd) postnatal week in rat) to develop quickly but it also makes it highly prone to age-specific seizures that can cause lifelong neurological and cognitive disability (Haut et al. 2004). There are three types of ionotropic glutamate ...

Bilateral intracerebroventricular infusion of dl-homocysteic acid (DL-HCA) (600 nmol on each side) to immature 12-day-old rats induced generalized clonic-tonic seizures, recurring frequently for at least 90 min, with a high rate of survival. Electrographic recordings from sensorimotor cortex, hippocampus, and striatum demonstrated isolated spikes in the hippocampus and/or striatum as the first sign of dl-HCA action. Generalization of epileptic activity occurred during generalized ...

PURPOSE: To study the possible relation between spontaneous recurrent seizures (SRS) and the derangement of cognitive memory.

METHODS: Status epilepticus (SE) was induced in adult Long-Evans rats by pilocarpine (320 mg/kg, i.p.) and interrupted after 2 h by clonazepam (CZPs mg/kg, i.p.). In addition to the animals that were given pilocarpine and CZP (group P), two groups received ketamine (100 mg/kg, i.p.): the first group 15 minutes after SE onset (group K15), and the second immediately ...

GYKI 52466 (1-(4-aminophenyl)-4-methyl-7,8-methylendioxy-5H-2,3-benzo-diaz epi ne), a non-competitive non-NMDA receptor antagonist, was tested against epileptic afterdischarges elicited by cortical stimulation in 12-, 18- and 25-day-old rats with implanted electrodes. Shortening of afterdischarges and a decrease in intensity of clonic movements accompanying both stimulation and afterdischarges were induced by the 20 mg/kg dose of GYKI 52466 in 18- and 25-day-old animals, whereas ...

GABA(B) receptors mediate inhibition at early stages of development but mixed anti-and proconvulsant action of their agonists affecting all receptors was found in immature rats. Positive allosteric modulators of GABA(B) receptors potentiate only already active GABA(B) receptors and therefore more specific action is expected. Possible anticonvulsant action of CGP7930 was studied in a model of pentetrazol-induced seizures previously used for studies with agonists baclofen and SKF97541. ...

The direct injection of endothelin-1 (ET-1) into brain parenchyma was recently suggested as a suitable model of stroke. The present study was designed to assess whether intrahippocampal injection of ET-1 in immature rats causes neurodegeneration and immediate seizures, and results in impairment of motor development, cognitive decline, epilepsy and chronic hippocampal lesion. ET-1 was injected unilaterally into the dorsal hippocampus in doses of 20 or 40 pmol at the age of 12 (P12) or 25 ...

Electrical stimulation of sensorimotor cortex was used to study early and late effects of administration of kainic acid in a dose (6 mg/kg i.p.) eliciting only nonconvulsive seizures in rats. Thresholds for elicitation of four phenomena--movements directly related to stimulation; epileptic afterdischarges (ADs) of the spike-and-wave type; clonic seizures accompanying these ADs; and mixed type of ADs where spike-and-wave activity transgresses into limbic type of epileptic phenomena--were ...