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M Morre

Publications and source records attributed to M Morre.

26 records · Page 2Linked to original sources
PubMed1984

The staircase test in mice: a simple and efficient procedure for primary screening of anxiolytic agents.

The staircase test consists of placing a naive mouse in an enclosed staircase with five steps and observing the number of steps climbed and rearings made in a 3-min period. All the clinically active anxiolytics tested (chlordiazepoxide, clorazepate, diazepam, lorazepam, meprobamate, phenobarbital) reduce rearing at doses which did not reduce the number of steps climbed. The majority of non-anxiolytic substances tested (haloperidol, chlorpromazine, imipramine, amitriptyline, amphetamine, morphine and carbamazepine) produced a parallel reduction of both behavioural variables. Ethosuximide had no effect on behaviour. The anticonvulsant sodium valproate produced an anxiolytic profile in this test, since it reduced rearing, while increasing step climbing. This result confirms the anxiolytic properties of valproate observed in other behavioural models. Our results indicate that the staircase test in mice is simple, rapid and selective for anxiolytics. The test is well suited for use as a primary screening method.

Animals↗
PubMed1983

Kappa binding sites in guinea-pig brain membranes: evidence for a dynorphin-resistant subtype.

Using [3H]ethylketocyclazocine after suppression of mu, delta and sigma binding by 100 nM DAGO + 100 nM DADLE + 10 microM phencyclidine we showed the existence of a subclass of kappa sites insensitive to dynorphins 1-9 and 1-17, and alpha and beta neoendorphins, but sensitive to the non-peptidic opiates. The dynorphin-sensitive site probably corresponds to the "standard" kappa site while the importance of the dynorphin-resistant site remains to be established.

Analgesics, Opioid↗
PubMed1983

The effects of analogues of valproic acid on seizures induced by pentylenetetrazol and GABA content in brain of mice.

The effect of valproic acid and 10 close analogues (7 branched and 3 non-branched) were studied on the content of gamma-aminobutyric acid (GABA) in brain and on seizures induced by pentylenetetrazol (PTZ) in mice. All 8 branched fatty acids protected against seizures induced by pentylenetetrazol, but the 3 non-branched acids were inactive. A significant correlation was observed between side-chain length and anticonvulsant potency. However, sedative and toxic phenomena became apparent with longer chain lengths. The 3 non-branched fatty acids did not alter levels of GABA in brain, but there was a significant correlation between anticonvulsant activity and increased brain GABA levels, for the 8 branched fatty acids. Despite this correlation, one branched analogue, 2-ethylbutyric acid, possessed anticonvulsant activity but did not increase the content of GABA in brain.

Animals↗
PubMed1983

[Is the benzodiazepine binding site a receptor?].

The benzodiazepines bind to high affinity sites on neuronal membranes in the central nervous system. These sites form part of a multimolecular postsynaptic complex which also includes the GABA receptor and its ionophore. The benzodiazepine binding sites appear to present a certain heterogeneity which may correspond to a diversity of functions. A good correlation exists between the pharmacological potencies of the various benzodiazepines and their affinities for the receptor in vitro, but the relationship is less clear when binding is studied in vivo. Nevertheless, high affinity benzodiazepine binding remains an essential tool for the pharmacologist in search of more specific drugs.

Animals↗
PubMed1982

Analgesia, new research approaches.

In the field of research of new centrally acting analgesics devoid of side effects, two Quo Vadis? symposia took place in Montpellier and Toulouse. The first was devoted to a review of the concept of enkephalinase inhibition: a specific protease for enkephalin inactivation. The second dealt with the existence of a kappa receptor, one of the opiate binding sites whose stimulation would not involve a respiratory depression and only induce limited tolerance and dependence phenomena.

Analgesics↗
PubMedDate not supplied

Benzodiazepine impairs and beta-carboline enhances performance in learning and memory tasks.

Benzodiazepines are widely used anxiolytics and anticonvulsants, and their potent sedative properties are routinely used in presurgical anaesthesia. However, they are also known to induce a strong anterograde amnesia in patients. Specific benzodiazepine antagonists have recently been described, some of which have intrinsic pharmacological properties that are opposite to those of benzodiazepines. These have been called inverse agonists and they have been shown to be proconvulsant or convulsant whereas benzodiazepines are anticonvulsants. Inverse agonists are also anxiogenic rather than anxiolytic. Since benzodiazepines induce anterograde amnesia, we have investigated the possibility that inverse agonists might also have an opposite effect for this property and so enhance acquisition (learning) and (or) retention (memory). We report here that, in three different animal models, an inverse agonist of the beta-carboline group, methyl beta-carboline-3-carboxylate (beta-CCM), enhances animal performance in three different tasks used to investigate learning and memory.

Animals↗