Different alcohol exposures induce selective alterations on the expression of dynorphin and nociceptin systems related genes in rat brain.

Molecular mechanisms of adaptive transformations caused by alcohol exposure on opioid dynorphin and nociceptin systems have been investigated in the rat brain. Alcohol was intragastrically administered to rats to resemble human drinking with several hours of exposure: water or alcohol (20% in water) at a dose of 1.5 g/kg three times daily for 1 or 5 days.

Olanzapine counteracts stress-induced anxiety-like behavior in rats.

Atypical antipsychotics, such as olanzapine, have been reported to display anxiolytic properties as shown in several preclinical and clinical studies. Furthermore, several experimental evidences have shown that olanzapine reduces fear and anxiety in activated anxiety-like behavior test such as Geller-Seifter test, ultrasonic vocalization test and stress-induced EtOH consumption. Here, we hypothesized that the anxiolytic action of olanzapine might be due to via an indirect activation of the gamma-amino butyric acid (GABA)-ergic system through 3alpha-hydroxy-5alpha-pregnan-20-one [allopregnanolone (ALLO)], a potent neuroactive steroid that positively modulates the benzodiazepine-gamma-aminobutyric acid type A (GABA(A))/benzodiazepine receptors complex.

Water T-maze, an improved method to assess spatial working memory in rats: Pharmacological validation.

The present study was performed to validate a spatial working memory task using pharmacological manipulations. The water escape T-maze combines the advantages of the Morris water maze and the T-maze while minimizing the disadvantages. Scopolamine (1mg/kg), a drug that affects cognitive function in spatial working memory tasks, significantly decreased the rats' performance in the present delayed alternation task.

Determination of Olanzapine in rat brain using liquid chromatography with coulometric detection and a rapid solid-phase extraction procedure.

A sensitive and selective method was developed for the determination of the antipsychotic drug Olanzapine levels in rat brain tissue, based on HPLC with electrochemical detection. The analyses were carried out on a C8 reversed phase column (150 mm x 4.6 mm, 5 microm), using a mobile phase composed of methanol and a phosphate buffer (44.

An ionotropic but not a metabotropic glutamate agonist potentiates the pharmacological effects of olanzapine in the rat.

This study aimed to evaluate the possible potentiating action of ionotropic or metabotropic (metabotropic glutamate receptor type 5) glutamate agonists on pharmacological effects induced in rats by the atypical antipsychotic olanzapine. The administration of doses of olanzapine, which did not affect spontaneous motility, inhibited behaviors induced by the selective stimulation of 5HT(2A) and D(2) receptors. In particular, 0.

Repeated administration of the novel antipsychotic olanzapine does not modulate NMDA-sensitive glutamate and 5HT2 serotonin receptors in rats.

Antipsychotic drugs reportedly show a common property in facilitating glutamatergic transmission in rat cerebral cortex. Since the binding of the radiolabelled channel blocker [3H]-MK801 is generally considered an affordable index of N-methyl-d-aspartate (NMDA)-sensitive glutamate receptor activation, we examined the effects of clinically effective treatment (3 weeks, daily administration) of the atypical antipsychotic drug olanzapine (32 micromol/kg/5 ml) on the specific binding of [3H]-MK801 specific binding and on the strychnine-insensitive glycine sites (glycine B) in synaptic plasma membranes (SPM) prepared from the medial prefrontal cortex (mPFC) of rats sacrificed after different (24, 60, 120 h) washout periods. We studied also the effects of repeated olanzapine administration on [3H]-ketanserin binding to 5HT2A receptors to verify whether, consistent with previously reported paradoxical effects of repeated administration of 5HT2A antagonists, this drug decreases 5HT2A receptor density without changing the apparent affinity.