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L Stéru

Publications and source records attributed to L Stéru.

8 recordsLinked to original sources
PubMed1988

Specificity of piracetam's anti-amnesic activity in three models of amnesia in the mouse.

The effects of piracetam on the amnesias induced by scopolamine, diazepam and electroconvulsive shock (ECS) were studied in a passive avoidance procedure in the mouse and compared with the interactions of piracetam with the major behavioral effects of these treatments, namely scopolamine-induced hyperactivity, diazepam-induced release of punished behavior (Four Plates Test) and ECS-induced convulsions. Amnesia was induced by injecting scopolamine or diazepam (1 mg/kg, IP) 30 minutes before or applying ECS immediately after the first session (S1) of the passive avoidance task. Piracetam was studied at 3 doses (512, 1024 and 2048 mg/kg) administered PO 60 minutes before S1. Retention was measured 24 hours later (S2) in the absence of any treatment. Piracetam dose-dependently attenuated the memory deficits induced by the three amnesic treatments but did not affect either scopolamine-induced hyperactivity, diazepam-induced release of punished behavior or ECS-induced convulsions. These results point to the specificity of piracetam's anti-amnesic activity and, in particular, suggest that piracetam can suppress the memory disturbances induced by diazepam without affecting diazepam's anxiolytic activity. The test battery employed would therefore seem highly suitable for evaluating the potential nootropic activity of novel compounds.

Amnesia↗
PubMed1987

Comparing benzodiazepines using the staircase test in mice.

Eleven benzodiazepines were evaluated in the staircase test in mice. The behavioural parameters measured were the number of steps climbed and the number of rears during a 3-min test. Climbing and to a lesser extent rears were enhanced at low doses, whereas both parameters, particularly rearing, were reduced at higher doses. The differential effects of the drugs on the two parameters were used to determine indices of anxiolytic efficacy for each drug where increases in climbing were taken to indicate the onset of anxiolytic activity and decreases in rearing the onset of sedative activity. The compounds could be ranked according to these indices in a manner which appears to reflect their therapeutic profile in man.

Animals↗
PubMed1987

The effects of exifone, a new agent for senile memory disorder, on two models of memory in the mouse.

The effects of exifone (ADLONE), hexahydro-2,3,4,3',4',5'-benzophenone, were tested in two models of memory in the mouse: habituation of exploratory activity and antagonism of amnesia induced by scopolamine in a passive avoidance task. In the first model, mice which had received exifone (128 and 256 mg/kg IP) 30 minutes before a 3 minute exposure to a staircase exploratory test showed a more marked decrease in exploratory activity in the same apparatus 24 hours later (habituation) than a control group indicating improved memory. Similar results were obtained with piracetam (512 mg/kg, IP). In the second model exifone (512 mg/kg PO), administered 60 minutes before both the learning and retention trials of a standard step-through passive avoidance, task partially antagonized the amnesia induced by 10 mg/kg scopolamine IP administered immediately after the learning trial. Similar results were obtained with piracetam (800 mg/kg PO). Taken together these results suggest that exifone facilitates memory function in simple rodent models in a manner consistent with its supposed therapeutic effects in man.

Amnesia↗
PubMed1987

Psychopharmacological profile of the new cognition enhancing agent exifone in the mouse.

Hexahydro-2,3,4,3',4',5'-benzophenone (exifone, Adlone), a novel compound proposed for treating cognitive dysfunction in geriatric patients, was tested in a battery of standard psychopharmacological tests in the mouse. The results indicated that the compound was non-toxic and induced no signs of overt stimulation or sedation after acute administration of oral doses up to 1024 mg/kg. The compound was devoid of anxiolytic, anticonvulsant or classical neuroleptic activity and did not antagonize the effects of reserpine or a high dose of apomorphine, two tests indicative of classical antidepressant activity. On the other hand, exifone clearly decreased the duration of immobility in the tail suspension test and antagonized the hypothermia induced by a low dose of apomorphine. The compound shortened the duration of barbital induced sleep without affecting the duration of sleep induced by pentobarbital. The effects observed suggest that exifone is not devoid of psychotropic activity and might possess some properties of an atypical antidepressant.

Animals↗
PubMed1987

Use of the automated tail suspension test for the primary screening of psychotropic agents.

Mice, when suspended by the tail, will alternate between active attempts to escape and immobility. A specially developed computerized device (ITEMATIC-TST) automatically measures the duration of immobility of 6 mice at one time and at the same time provides a measure of the energy expended by each animal, the power of the movements. Use of these 2 parameters enables activity profiles to be generated which can distinguish different classes of psychotropic activity. Immobility is decreased by antidepressants and psychostimulants, but increased by neuroleptics and minor tranquillizers. Minor tranquillizers can be distinguished from neuroleptics in that they decrease the power of the movements, whereas neuroleptics are without effect on this parameter. The present experiments were undertaken to see whether the activity profiles generated in this procedure could indeed be useful for primary psychotropic screening. Eighteen compounds, including antidepressants, neuroleptics, minor tranquillizers, sedative/hypnotics, dopaminergic stimulants and 3 dummy compounds were first submitted to a shortened primary observation procedure for dose finding and were then investigated at 2 doses in the automated tail suspension test. All experiments were conducted blind. The results obtained largely confirm the activity profiles already reported in this test and show that the combined use of primary observation and the automated tail suspension test permit the unambiguous identification of the pharmacological activity of 15 of the compounds tested with tentative identification of the 3 remaining compounds.

Animals↗
PubMed1986

Comparative study in mice of ten 1,4-benzodiazepines and of clobazam: anticonvulsant, anxiolytic, sedative, and myorelaxant effects.

We will present data from the comparison between four tests in mice of 10 1,4-benzodiazepines and one 1,5-benzodiazepine (clobazam). The tests used were: the "4 plates test" of anxiolytic activity; the electroshock test to determine the anticonvulsive effects; actimetry to predict the sedative effect on motricity; and traction test to predict the myorelaxant effect. The latter two tests have been suggested to be predictive of side-effects that damage psychomotor efficiency in human patients. A comparison of ED50s determined from the predictive tests of the therapeutic effect and those of the side-effects led to the calculation of ratios considered to be predictive of the safety margin. A classification according to this margin shows the advantages of the 1,5-benzodiazepine compared with the 1,4-benzodiazepines. Despite the caution needed in the extrapolation of the results from animals to humans, this work stresses the interesting place that the 1,5-benzodiazepine seem to hold as anticonvulsant in clinical practice.

Animals↗