Differential effects of the MEK inhibitor SL327 on the acquisition and expression of ethanol-elicited conditioned place preference and aversion in mice.

The involvement of mitogen-activating extracellular kinase (MEK) in place conditioning may vary depending on the motivational sign (positive or negative) and nature (pharmacological or nociceptive) of the unconditioned stimulus (US) and on the phase (acquisition or expression) of the learning process. This study investigated the role of MEK on the acquisition and expression of ethanol-elicited (given 2 g/kg) backward (preference, CPP) and forward (aversion, CPA) place conditioning. The MEK inhibitor SL327 (50 mg/kg for CPP, and 50 and 100 mg/kg for CPA) was administered to CD-1 mice 60 minutes before an ethanol dose (acquisition) or 60 minutes before the post-conditioning tests (expression).

Withania somnifera Dunal (Indian ginseng) impairs acquisition and expression of ethanol-elicited conditioned place preference and conditioned place aversion.

Withania somnifera Dunal (Indian Ginseng) has recently been shown to impair ethanol self-administration. In order to gain further insights on the ability of the Withania somnifera standardised root extract (WSE) to affect the motivational properties of ethanol, this study investigated whether WSE may also affect ethanol (2 g/kg)-elicited conditioned place preference (CPP) and aversion (CPA). To this end male CD-1 mice were conditioned under two distinct schedules: in backward conditioning experiments ethanol was administered before mice were placed in the conditioning apparatus (CPP) while, in forward conditioning experiments, ethanol was administered immediately after removing mice from the apparatus (CPA).

Withania somnifera prevents acquisition and expression of morphine-elicited conditioned place preference.

Previous studies have reported that some of the central effects of morphine are counteracted by the administration of the methanolic extract of the root of Indian ginseng, Withania somnifera Dunal (WSE). The present study sought to determine whether WSE affects acquisition and expression of morphine-elicited conditioned place preference (CPP) in CD-1 mice. In CPP acquisition experiments, WSE (0, 25, 50, and 100 mg/kg) was administered, during conditioning, 30 min before morphine (10 mg/kg), whereas in expression experiments, WSE (0, 25, 50, and 100 mg/kg) was administered 30 min before the postconditioning test.

Piecing together the puzzle of acetaldehyde as a neuroactive agent.

Mainly known for its more famous parent compound, ethanol, acetaldehyde was first studied in the 1940s, but then research interest in this compound waned. However, in the last two decades, research on acetaldehyde has seen a revitalized and uninterrupted interest. Acetaldehyde, per se, and as a product of ethanol metabolism, is responsible for many pharmacological effects which are not clearly distinguishable from those of its parent compound, ethanol.

The MEK inhibitor SL327 blocks acquisition but not expression of lithium-induced conditioned place aversion: a behavioral and immunohistochemical study.

Rationale: Recent evidence involves extracellular signal-regulated kinase (ERK) in positive motivational properties of drugs as determined by conditioned place preference but, to date, its role in conditioned place aversion (CPA) still awaits to be fully characterized.

Objectives: The aim of this study was to assess whether activated ERK (pERK) plays a role in the acquisition and/or expression of lithium-induced CPA.

Methods: C57BL/6J mice were subjected to lithium (150 mg/kg)-induced CPA.

Pharmacological activities on Ephedra nebrodensis Tineo.

As a part of our endeavour to screen Mediterranean medicinal plants for various pharmacological activities, we evaluated antihistaminic, adaptogenic, anti-inflammatory, antinociceptive, hypotensive and locomotor properties, and antioxidant potential of Ephedra nebrodensis. (1)H-NMR spectroscopy was carried out to identify the plant metabolites, which confirmed the presence of ephedrinic skeleton alkaloids. The ethanol : acetone (1 : 1) extract exhibited dose-related antihistaminic, anti-inflammatory, antinociceptive, hypotensive, antioxidant and locomotor stimulant activity.

Acetaldehyde elicits ERK phosphorylation in the rat nucleus accumbens and extended amygdala.

Recent advances suggest that acetaldehyde mediates some of the neurobiological properties of ethanol. In a recent study, we have shown that ethanol elicits the phosphorylation of extracellular signal-regulated kinase (pERK) in the nucleus accumbens and extended amygdala, via a dopamine D(1) receptor-mediated mechanism. The aim of this study was to determine whether acetaldehyde and ethanol-derived acetaldehyde elicit the activation of ERK in the nucleus accumbens and extended amygdala.

Role of dopamine D1 receptors and extracellular signal regulated kinase in the motivational properties of acetaldehyde as assessed by place preference conditioning.

Background: The role of dopamine D1 receptors and Extracellular signal Regulated Kinase (ERK) in the motivational properties of drugs can be studied by place-conditioning. Recent advances have shown that the motivational properties of ethanol, determined by place-conditioning, are mediated by its metabolic conversion into acetaldehyde. To date, the role of D1 receptors and ERK activation in acetaldehyde-elicited place preference has not been determined.

Assessment of symptomatic and neuroprotective efficacy of Mucuna pruriens seed extract in rodent model of Parkinson's disease.

Mucuna pruriens (MP) has long been used in Indian traditional medicine as support in the treatment of Parkinson's disease. However, no systematic preclinical studies that aimed at evaluating the efficacy of this substance are available to date. This study undertook an extensive evaluation of the antiparkinsonian effects of an extract of MP seeds known to contain, among other components, 12.

Ethanol-induced extracellular signal regulated kinase: role of dopamine D1 receptors.

Background: Addictive drugs activate extracellular signal regulated kinase (ERK) in brain regions critically involved in their affective and motivational properties. The aim of this study was to demonstrate the ethanol-induced activation of ERK in the nucleus accumbens (Acb) and in the extended amygdala [bed nucleus of the stria terminalis lateralis (BSTL) and central nucleus of the amygdala (CeA)] and to highlight the role of dopamine (DA) D(1) receptors in these effects.

Methods: Ethanol (0.

Morphine-conditioned single-trial place preference: role of nucleus accumbens shell dopamine receptors in acquisition, but not expression.

Rationale: A large body of evidence indicates an involvement of the mesolimbic dopamine (DA) pathway innervating the ventral striatum in the motivational effects of drug abuse.

Objective: The goal of the study is to clarify the role of DA D1 and D2 receptors of the rat nucleus accumbens (NAc) shell and core in the motivational effects of morphine as studied by conditioned place preference (CPP).

Methods: The effect of the intracerebral infusion of DA antagonists specific for DA D1 (SCH 39166) and D2 receptors (L-sulpiride) was studied in a single-trial place conditioning paradigm with fixed assignment of the drug to the unpreferred compartment.

Nicotine-conditioned single-trial place preference: selective role of nucleus accumbens shell dopamine D1 receptors in acquisition.

Rationale: Experimental evidence indicates that the mesolimbic dopamine (DA) pathway innervating the ventral striatum is critically involved in the motivational effects of drug abuse. However, the role of DA transmission of the two main subdivisions of the nucleus accumbens (NAc), the shell and the core, in the motivational properties of nicotine is unknown.

Objectives: The aim of this study was to investigate the role of DA D1 and D2 receptors of the rat NAc shell and core in the motivational effects of nicotine using a conditioned place preference (CPP) paradigm.

Dopamine-dependent behavioural stimulation by non-peptide delta opioids BW373U86 and SNC 80: 2. Place-preference and brain microdialysis studies in rats.

The motivational properties of the non-peptide delta-opioid receptor agonists BW373U86 and SNC 80 were investigated using the place-conditioning paradigm. BW373U86 (0.5-1.

Dopamine-dependent behavioural stimulation by non-peptide delta opioids BW373U86 and SNC 80: 1. Locomotion, rearing and stereotypies in intact rats.

The unconditioned behavioural effects of two non-peptide delta-opioid receptor agonists, BW 373U86 and SNC 80, were studied in the intact rat. BW 373U86 (0.1-2.

(D-Ala2)deltorphin II: D1-dependent stereotypies and stimulation of dopamine release in the nucleus accumbens.

In order to investigate the relative role of central delta- and mu-opioid receptors in behavior, the effects of (D-Ala2)deltorphin II, a natural delta-opioid peptide, and PL017, a beta-casomorphin derivative specific for mu receptors, were compared after local intracerebral and intraventricular administration. Intracerebral infusion of the two peptides was done bilaterally in the limbic nucleus accumbens and in the ventral and dorsal caudate putamen of freely moving rats through chronic intracerebral cannulas. After intra-accumbens infusion, the two peptides elicited marked but opposite behavioral effects: while (D-Ala2)deltorphin II evoked dose-dependent motor stimulation characterized by locomotion, sniffing, and oral stereotypies, PL017 elicited motor inhibition with rigidity and catalepsy.

SKF 38393 potentiates yawning induced by LY 171555: further evidence against the autoreceptor hypothesis of yawning.

The effect of concurrent D-1 receptor stimulation by SKF 38393 on the expression of yawning elicited by D-2 receptor stimulation with LY 171555 was studied in the rat. A low dose of SKF 38393 (2.5 mg/kg SC), while failed to elicit yawning, potentiated the effectiveness of LY 171555 in eliciting yawning at all the doses tested (12.

Permissive role of D-1 receptor stimulation for the expression of D-2 mediated behavioral responses: a quantitative phenomenological study in rats.

The syndrome of behavioral stimulation induced in male Sprague-Dawley rats by two dopaminergic agents was studied by distinguishing specific behavioral items and quantifying them in terms of their incidence. The specific D-2 agonist LY 171555 elicited yawning, genital grooming, exploratory behavior, downward sniffing and licking but failed to induce gnawing even at high doses. On the other hand, the D-1/D-2 agonist apomorphine elicited the full stereotyped syndrome including gnawing.

Permissive role of D-1 receptor stimulation by endogenous dopamine for the expression of postsynaptic D-2-mediated behavioural responses. Yawning in rats.

Low doses of BHT 920, LY 171555 and (+)3PPP, three dopamine agonists selective for D-2 receptors, induced yawning in rats. This effect was reduced by the selective D-1 antagonist SCH 23390 but the antagonism did not exceed a 50% reduction from the control values. In contrast, the selective D-2 antagonist (-)sulpiride completely abolished agonist-induced yawning.

Dopaminergic D-1 receptors: essential role in morphine-induced hypermotility.

Administration of morphine HCl (20 mg/kg SC) to male C57Bl/6 mice evoked hypermotility. Pretreatment with low doses of the specific D-1 antagonist SCH 23390 (0.006, 0.

SCH 23390 antagonizes apomorphine- and ergot-induced hypothermia.

The reportedly specific D-1 dopamine (DA) receptor antagonist SCH 23390 significantly reduced the hypothermia elicited by various DA receptor agonists like apomorphine, pergolide and lisuride. When tested against equihypothermic doses of each agonist, SCH 23390 significantly reduced the hypothermia elicited by apomorphine (0.2 mg/kg s.

Antagonism of apomorphine-induced yawning by SCH 23390: evidence against the autoreceptor hypothesis.

The ability of apomorphine to induce yawning (YWG) in normal and reserpinized rats and its interaction with SCH 23390, a potent and specific D-1 receptor antagonist, was studied. Apomorphine was more potent in inducing YWG in reserpine-pretreated as compared to control rats. SCH 23390, in low doses (0.

[Validity of the H2 breath test and limits of blood xylose in the evaluation of malabsorption in children].

Many authors have recently discussed the real value of the xylose test in the evaluation of intestinal malabsorption, especially its correlation with the morphological damage of the duodenal-jejunal mucosa. In our study we have performed in 48 pediatric patients one-hour blood xylose test and breath H2 test, method used for the diagnosis of sugar malabsorption, in order to value small bowel function and to know indirectly small intestinal mucosal structure. We have compared the values of the xylose test with those of the breath H2 test and both with hystological findings.

Ipsiversive turning behaviour after discrete unilateral lesions of the dorsal mesencephalic reticular formation by kainic acid.

Discrete axon-sparing lesions were placed unilaterally in the mesencephalon by the local injection of kainic acid. Unilateral lesions of the dorsal reticular formation just beneath the superior colliculus and lateral to the periacqueductal grey resulted in consistent ipsiversive apomorphine-induced circling. Only weak motor asymmetries were observed after unilateral lesions restricted to the superior colliculus or to the periacqueductal grey.