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G Chapouthier

Publications and source records attributed to G Chapouthier.

77 records · Page 5Linked to original sources
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Convulsions induced by methyl beta-carboline-3-carboxylate in mice: effects of preceding saline injections.

The convulsant effects of a high (5 mg/kg intraperitoneally, i.p.) dose of benzodiazepine (BZD) receptor ligand methyl beta-carboline-3-carboxylate (beta-CCM), whether or not preceded by administration of two lower doses of beta-CCM (0.5 and 1 mg/kg i.p.) or of saline were studied in nine inbred mouse strains. In five of the strains (A/J, BALB/cBy, C3H/HeJ, CBA/H, and DBA/2J), neither saline nor preceding injections of beta-CCM had any effect on subsequent reactivity to the subsequent convulsant dose. In the other 4 strains, such injections induced either tolerance (CPB-K, NZB), or sensitization (C57BL/6J, XLII), whatever the compound subsequently administered (beta-CCM or saline). In these strains, the data rule out any tolerance or sensitization effect due to beta-CCM, but suggest that such effects could be due to injection itself.

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Effects of convulsant ligands of the GABA-benzodiazepine receptor complex in conflict and learning tasks in mice.

A systematic study of the effects of convulsants acting at the GABA-benzodiazepine receptor complex was undertaken in mice to estimate their potential anxiogenic effects and/or performance enhancing effects in learning and memory tasks. Anxiogenic effects were assessed in a conflict task where lever presses delivered both a food pellet and a mild electric foot shock. Effects on learning were assessed through analysis of habituation to a new environment. The convulsant agents pentylenetetrazol (PTZ) and picrotoxin (PX), both acting through the GABA-benzodiazepine receptor complex, and strychnine, a convulsant acting through the glycine transmission were used. Our data show that non convulsive doses of PTZ (25 mg/kg) and PX (0.85 mg/kg), but not of strychnine (0.8 mg/kg), are anxiogenic in the conflict model. At lower doses PTZ (10 mg/kg) and PX (0.3 mg/kg), but not strychnine (0.1 to 0.6 mg/kg), enhance performance in the habituation model. Our results contribute to the validation of the idea that small decreases in GABAergic transmission are accompanied by improvement of learning whereas medium decreases induce anxiogenic effects.

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[Contribution of studies on animal memory to understanding human memory].

Studies of animal memory have contributed to the understanding of human memory from two points of view. Phylogenetic comparison of memory abilities in different animal groups demonstrates that human memory is a heterogeneous combination of various abilities, of different complexities, which appeared during the evolution. On the other hand, the use of animal models promotes better understanding of the physiological mechanisms underlying human memory. These models can be anatomic ones founded on the functional implication of encephalic areas, bioelectric ones founded on the implication of microscopic or macroscopic bioelectric phenomena or chemical ones founded on the molecular activity of the nervous system.

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