Search results for "LPI"
showing 10 items of 535 documents
A "double hit" murine model for schizophrenia shows alterations in the structure and neurochemistry of the medial prefrontal cortex and the hippocamp…
2013
Both alterations in neurodevelopment and aversive experiences during childhood and adolescence seem important risk factors for schizophrenia. Animal models reproducing these alterations mimic some of the symptoms, constituting a valid approach to study the etiopathology of this disorder. Among these models, the perinatal injection of N-methyl-d-aspartate receptor antagonists and the postweaning social isolation rearing are among the most widely used. Our aim is to combine them in a "double hit" model, which should produce a wider spectrum of alterations. Lister Hooded rats have been subjected to a single injection of MK-801 at postnatal day 7 and socially isolated from postweaning to adulth…
Neural overexcitation and implication of NMDA and AMPA receptors in a mouse model of temporal lobe epilepsy implying zinc chelation.
2006
Summary: Purpose: Zinc chelation with diethyldithiocarbamate (DEDTC) during nondamaging kainic acid administration enhances excitotoxicity to the level of cell damage. The objective of this work was to study the developing of the lesion in this model of temporal lobe epilepsy and the implications of the different types of glutamate receptors. Methods: The antagonist of the N-methyl-d-aspartate (NMDA) receptor MK-801, and the antagonist of the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA) receptor GYKI52466, were used concomitantly with intraperitoneal administration of kainic acid (15 mg/kg) followed by DEDTC (150 mg/kg) in mouse. The animals were killed at different times from 4 …
First spermatological data on the digenean genus Ityogonimus derived from the description of sperm characters of Ityogonimus ocreatus (Brachylaimidae…
2021
Abstract The present study describes the ultrastructural organization of the spermatozoa of the brachylaimid digenean Ityogonimus ocreatus (Ityogoniminae) by means of transmission electron microscopy (TEM). Live digeneans were collected from the digestive tract of an Iberian mole Talpa occidentalis (Eulipotyphla, Talpidae) captured accidentally during a vole pest control campaign in Priesca (Asturias, Spain). The TEM study reveals that the I. ocreatus sperm are filiform, tapered at both extremities, and have two 9+'1' trepaxonematan axonemes, external ornamentation of the plasma membrane associated with cortical microtubules, spine-like bodies, two bundles of parallel cortical microtubules …
Effects of the serjania erecta and zeyheria montana ethanol extracts in experimental pulpitis in rats: A histological study
2012
Objectives: The aim of this study was to evaluate, by the semi-quantitative histological analysis, the anti-inflammatory activity of the ethanolic extracts of Serjania erecta e Zeyheria Montana, in experimental pulpits in rats. Study Design: In order to induce pulp inflammation, cavities were performed on the occlusal surface of the mandibular first molars of 45 male rats, without pulp exposure. The animals were distributed into 4 groups: GI, teeth without cavities; GII, single dose of saline solution via intraperitoneal (IP); GIII, single dose (IP) of 300mg/Kg of ethanolic extract of Zeyheria montana; GIV, single dose (IP) of 300mg/Kg of ethanolic extract of Serjania erecta. After 6, 12 an…
NMDA-GABA interactions in an animal model of behaviour: a gating mechanism from motivation toward psychotic-like symptoms
1994
We studied the effects of desipramine, alprazolam, muscimol and dizocilpine (MK-801) (alone or associated with desipramine) in the forced swimming test in rats after long-lasting termination of chronic exposure to vehicle and pentylenetetrazol. Sensitisation with pentylenetetrazol was ineffective in changing immobility time in the forced swimming test compared to vehicle treatment; pentylenetetrazol enhanced the anti-immobility effect of desipramine, abolished the anti-immobility effect of alprazolam and did not affect the anti-immobility effect of muscimol. MK-801 at the dose that did not modify immobility time in vehicle-treated rats and in pentylenetetrazol-treated animals strongly poten…
Morphine potentiates the impairing effects of neuroleptics on two-way active conditioned avoidance response in male mice
2004
The dopaminergic and opioid systems have effects on the conditioned avoidance response (CAR), although the possible interaction between these systems on this behaviour has not been studied. The effects of morphine (12.6 mg/kg), haloperidol (0.075 mg/kg), sulpiride (20 mg/kg) and risperidone (0.1 mg/kg) alone as well as morphine combined with these dopamine (DA) antagonists on the acquisition and performance of the CAR were explored in mice. Morphine increased avoidances but this seemed secondary to a rise in activity levels. All DA antagonists impaired CAR in the acquisition phase but only haloperidol disrupted performance. The combination of morphine plus neuroleptics impaired acquisition …
Memantine presents different effects from MK-801 in motivational and physical signs of morphine withdrawal
2003
Adaptive changes in neural systems due to chronic opiate exposure are related to the neural plasticity phenomenon, NMDA receptors being implicated in these processes, e.g. tolerance, dependence or withdrawal. In this work, we investigated the effect of two non-competitive NMDA antagonists, memantine and MK-801, in motivational (Conditioned Place Aversion paradigm, CPA) and physical aspects of morphine withdrawal. After the induction of morphine dependence, animals in which the CPA was studied, received memantine (5 and 10 mg/kg) or MK-801 (0.3-0.006 mg/kg) either during the acquisition (conditioning) or expression (test) phase of this procedure. Both drugs were capable of inhibiting conditi…
The effects of dopamine D 2 and D 3 antagonists on spontaneous motor activity and morphine-induced hyperactivity in male mice
1999
Rationale: Dopaminergic neurotransmission, in particular the mesolimbic pathway, is involved in spontaneous locomotor activity and in morphine-induced hyperactivity, since the drugs acting on DA receptors can modify the action of morphine and this effect could be dependent on the type of DA receptor affected. Objective: In this study, the action of U-99194A maleate, haloperidol, sulpiride and morphine (5, 10, 20, 40 mg/kg) on locomotor activity in male mice was evaluated. Likewise, the effects of these dopaminergic antagonists on morphine-induced hyperactivity were studied. Methods: Animals treated with U-99194A maleate (2.5, 5, 10, 20 mg/kg), haloperidol (0.075, 0.1 mg/kg), sulpiride (20, …
Nicotinic and muscarinic modulation of 5-hydroxytryptamine (5-HT) release from porcine and canine small intestine
1992
Strips of porcine and canine small intestine were incubated in vitro and the release of 5-hydroxytryptamine (5-HT) was determined by HPLC with electrochemical detection. The spontaneous outflow of 5-HT from the porcine and canine small intestine largely reflects calcium-dependent 5-HT secretion from enterochromaffin cells which are under a spontaneous neuronal, excitatory input as indicated by the inhibitory effect (30-40%) of tetrodotoxin. In both species, nicotine enhanced the release of 5-HT in a concentration-dependent manner by a maximum of about 50% at 100 microM. This effect was blocked by the nicotine receptor antagonist hexamethonium, but not by the subtype-selective nicotine recep…
Phenytoin-induced glutathione depletion in rat peripheral nerve
1995
Abstract Administration of high doses (150–250 mg/kg body weight) of phenytoin (DPH) promote a 40% decrease in glutathione (GSH) content of rat sciatic nerve. This DPH-induced GSH depletion is accompanied with an electrophysiological impairment of peripheral neuromuscular function. H7 (20 mg/kg body weight IP, 30 min prior to DPH), a protein kinase C inhibitor, was able to prevent the DPH-induced GSH depletion only at the lower DPH dose used. This same inhibitor completely prevented the electrophysiological impairment at the lower DPH dose, and only partially at the higher DPH dose used. These results confirm the hypothesis of a DPH-dependent activation of PKC (that might be triggered by, o…