Threshold intensities for epileptic phenomena induced by cortical stimulation were used for comparison of the action of GABA-B and GABA-A antagonists in rats with implanted electrodes. Both CGP 35348 (200 mg/kg i.p.) and bicuculline (4 mg/kg i.p.) significantly decreased thresholds for spike-and-wave afterdischarges and their motor counterpart (clonic seizures) whilst transition into the second, limbic type of afterdischarge as well as threshold for movements directly bound to stimulation remained uninfluenced by either drug., D. Živanović, K. Bernášková, Yu. Kaminskij, P. Mareš., and Obsahuje bibliografii
Metabotropic glutamate receptors (mGluRs) represent a potential therapeutic target. Possible anticonvulsant action of AMN 082, an agonist of mGluR7 subtype, was studied in immature rats using pentylenetetrazol (PTZ)-induced seizures as a model. Five age groups of rats (7-, 12-, 18-, 25-day-old and adult animals) were pretreated with AMN 082 in doses of 0.5, 1, 2, and 5 mg/kg i.p. and 30 min later PTZ was administered (100 mg/kg s.c.). Controls received saline instead of the agonist. AMN 082 did not exhibit clear anticonvulsant action with the exception of suppression of the tonic phase of generalized tonic-clonic seizures (GTCS) in 12-day-old rats. Shorter latencies of GTCS after AMN 082 pretreatment indicate a proconvulsant action. Involuntary movements (mostly tremor) appeared after AMN 082 before PTZ administration, therefore we performed another experimental series with AMN 082 only (1, 2, 5, and 10 mg/kg i.p.). During 60-min observation period tremor appeared in all age groups; sensitivity to this action decreased with age from the 2 mg/kg dose in 7- and 12-day-old rats to the 10 mg/kg dose in adult rats. Mixed anti- and proconvulsant actions of AMN 082 together with unwanted motor effects makes clinical use of this drug highly improbable., Pavel Mareš., and Obsahuje bibliografii a bibliografické odkazy
The possible protective action of L-carnitine on neuronal excitability was studied in 21-day-old male Wistar rats with implanted electrodes. Administration of L-carnitine did not change the elicitation and duration of the epileptic seizures (cortical afterdischarges, ADs) in rats under normobaric oxygen atmosphere conditions. However, in animals exposed to 30 min hypobaric hypoxia the duration of the ADs was shortened after the second, fourth and sixth stimulation (in comparison with the first evoked ADs) while carnitine-treated rats retained their neuronal excitability and the duration of ADs was shortened only after the third stimulation., D. Marešová, H. Rauchová, K. Jandová, I. Valkounová, J. Koudelová, S. Trojan., and Obsahuje bibliografii