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Results 301 - 350 of 1829
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Zheng Min - - 2006
AIM: To study the effect of ZD7288 on synaptic transmission in the pathway from perforant pathway (PP) fibers to CA3 region in rat hippocampus. METHODS: The extracellular recording technique in vivo was used to record the CA3 region field potentials. High-performance liquid chromatography (HPLC) with fluorescence detection was applied to ...
Yoon SeungYong - - 2006
Calpain activation has been implicated in the pathogenesis of Alzheimer's disease. Okadaic acid, a protein phosphatase-2A inhibitor, has been used in Alzheimer's disease research models to increase tau phosphorylation and induce neuronal death. We previously reported that okadaic acid induced predominant activation of caspase-3 in immature neurons, but less activation ...
Longoni M - - 2006
The pathogenesis of migraine is still unclear, but much evidence suggests a role of inflammation in pain generation. Calcitonin gene related peptide, nitric oxide and cytokines are all molecules shown to be involved both in animal and human studies. The glutamatergic system is also described as a possible mechanism leading ...
Lin Yi-Ruu - - 2006
The aim of the present study was to investigate the neuroprotective effects of honokiol and magnolol, two major bioactive constituents of the bark of Magnolia officinalis, against neuron toxicity induced by glucose deprivation, excitatory amino acids and hydrogen peroxide (H(2)O(2)) in cultured rat cerebellar granule cells. Cell membrane damage was ...
Chen Xuanmao - - 2006
Acid-sensing ion channels are excitatory receptors for extracellular H+. Since the extracellular H+ concentration can significantly increase during an inflammation, one of the proposed functions for ASICs is peripheral perception of pain. The ASIC1b and ASIC3 subunits are specifically expressed in sensory ganglia neurons and are candidate sensors of peripheral ...
Canu Marie-Hélène MH Unité de Neurosciences et Physiologie Adaptative, Groupe Plasticité Neuromusculaire, Université des Sciences et Technologies de Lille, 59655, Villeneuve d'Ascq Cedex, France. - - 2006
Hindlimb unloading is considered as a model of functional deafferentation, since in this situation the tactile information from the paw and the proprioceptive input from the limb are dramatically reduced. Unloading induces a shrinkage of the cortical representation of the affected body part associated to a reorganization of topographic maps ...
Succu Salvatora - - 2006
The cannabinoid CB1 receptor antagonist SR 141716A (0.1, 0.5 and 1 microg) induces penile erection when injected into the paraventricular nucleus of the hypothalamus of male rats. The pro-erectile effect of SR 141716A occurs concomitantly with an increase in the concentration of glutamic acid in the paraventricular dialysate obtained by ...
Nicolai Joost - - 2006
This report presents a male who developed clonic seizures on the day he was born. The next day, the diagnosis of pyridoxine-dependent seizures was made. However, contradictory to this diagnosis, seizures reappeared despite treatment with pyridoxine. Seizures ceased after folinic acid was initiated. The clinical and biochemical characteristics of folinic ...
Wang Ze-Jian - - 2006
Stearic acid is a long-chain saturated fatty acid consisting of 18 carbon atoms without double bonds. In the present study, we reported the neuroprotective effects and mechanism of stearic acid on cortical or hippocampal slices insulted by oxygen-glucose deprivation, NMDA or hydrogen peroxide (H(2)O(2)) in vitro. Different types of models ...
Jin Y H - - 2006
Behavioral evidence supports a role for peripheral glutamate receptors in normal nociceptive transmission. In this study, we examined the release of the excitatory amino acids, glutamate and aspartate, in the s.c. perfusate of the rat hind instep by in vivo microdialysis. Antidromic stimulation of the sciatic nerve and noxious stimuli ...
Titz Stefan - - 2006
The Cl(-)-extruding neuron-specific K(+)-Cl(-) cotransporter KCC2, which establishes hyperpolarizing inhibition, can transport NH(4) (+) instead of K(+). It is, however, not clear whether KCC2 provides the only pathway for neuronal NH(4) (+) uptake. We therefore investigated NH(4) (+) uptake in cultured rat brain neurons. In neurons cultured for > 4 ...
Németh H - - 2006
The kynurenine pathway is the main pathway of tryptophan metabolism. L-kynurenine is a central compound of this pathway since it can change to the neuroprotective agent kynurenic acid or to the neurotoxic agent quinolinic acid. The break-up of these endogenous compounds' balance can be observable in many disorders. It can ...
Jandová K - - 2006
Using histochemical analysis the effect of intraperitoneal administration of kainic acid on hippocampal neurons was studied. 18-day-old male rats of the Wistar strain received kainic acid (10mg/kg) in one dose. Two days later, the 20-day-old animals were transcardially perfused with 4% paraformaldehyde under deep thiopental anaesthesia. Cryostat sections were stained ...
Rami Guillaume - - 2006
Dendritic spines are morphing structures believed to provide a cellular substrate for synaptic plasticity. It has been suggested that the actin cytoskeleton is the target of molecular mechanisms regulating spine morphology. Here we hypothesized that acidic calponin, an actin-binding protein, is one of the key regulators of actin filaments during ...
Kodama T - - 2006
Nitric oxide released from the cholinergic neurons in the pons may play important roles in sleep-wake regulation. However, there are few reports demonstrating the mechanisms of nitric oxide release in the cholinergic neurons in the pons. The present study investigated the effects of drug delivery of N-methyl-D-aspartic acid on nitric ...
Rae Caroline - - 2006
A range of behaviours are elucidated via ionotropic glutamate receptors (iGluR). In this work, we examined the acute activation of iGluRs by a range of receptor ligands and effectors to see whether distinguishable metabolic sequelae were elucidated by the activity. We used a guinea-pig brain cortical tissue slice model using ...
Rigoni Michela - - 2005
Snake presynaptic phospholipase A2 neurotoxins (SPANs) paralyze the neuromuscular junction (NMJ). Upon intoxication, the NMJ enlarges and has a reduced content of synaptic vesicles, and primary neuronal cultures show synaptic swelling with surface exposure of the lumenal domain of the synaptic vesicle protein synaptotagmin I. Concomitantly, these neurotoxins induce exocytosis ...
Nagy Gy?rgy M - - 2005
This article provides an overview of the increasing number of observations indicating that excitatory amino acids are involved in the control of prolactin secretion. The information available suggests that these amino acids exert a stimulatory action on hypophysial prolactin. Administration of a glutamate receptor agonist induces significant increase in prolactin ...
Skyba D A - - 2005
Chronic muscle pain is common and often difficult to treat. In this study, we further characterize a model of chronic muscle pain induced by repeated intramuscular injection of acidic saline. Two injections of acid into muscle separated by 5 days result in secondary mechanical hyperalgesia that lasts for up to ...
Sinniger Valérie - - 2005
Nor-trimebutine is the main metabolite of trimebutine that is used in the treatment of patients with irritable bowel syndrome. Nor-trimebutine has a blocking activity on sodium channels and a potent local anesthetic effect. These properties were used to investigate the effect of nor-trimebutine on spinal neuronal activation induced by models ...
Sokka Anna-Leena - - 2005
Prolonged or excess stimulation of excitatory amino acid receptors leads to seizures and the induction of excitotoxic nerve cell injury. Kainic acid acting on glutamate receptors produces degeneration of vulnerable neurons in parts of the hippocampus and amygdala, but the exact mechanisms are not fully understood. We have here investigated ...
de Pablos Rocío M - - 2005
We have tested the effect of deprenyl on the neurotoxicity induced by the injection of quinolinic acid within the striatum. Deprenyl was unable to prevent these quinolinic acid-induced damages, but enhanced the loss of several gamma-aminobutyric acid (GABA) positive subpopulations, the loss of the astroglial population and the activation of ...
Michalodimitrakis Konstantinos M - - 2005
Taz is a chimeric receptor consisting of the periplasmic, transmembrane and most of the HAMP linker domains of the Escherichia coli aspartate receptor (Tar(Ec)) and the cytoplasmic signalling domain of the E. coli osmosensor EnvZ. Aspartate is one of several attractant ligands normally sensed by Tar and it interacts with ...
Yoon Myung Ha - - 2005
Adenosine and excitatory amino acids have been known to be involved in modulating nociceptive transmission at the spinal level. The authors assessed the characteristics of the interaction of the adenosine-excitatory amino acid antagonist combinations in the spinal cord of rats on the formalin-induced nociception. Intrathecal NMDA antagonist ((5R, 10S)-(+)-5-methyl-10,11-dihydro-(5)H-dibenzo[a[,]d]cyclohepten-5,10-imine hydrogen ...
Zhang Zhiren - - 2005
Effects of repeated intraperitoneal injections of polyinosine-polycytidylic acid on spinal cord cells were analysed. After each injection, the number of ED-1 microglia significantly increased in rat spinal cords. Expression of endothelial monocyte-activating polypeptide II, however, was not observed. The morphology of microglia indicated an incomplete activation state even after three ...
Pantaleo T - - 2005
The role of the Bötzinger complex (BötC) and the pre-Bötzinger complex (pre-BötC) in the genesis of the breathing pattern was investigated in anesthetized, vagotomized, paralysed and artificially ventilated rabbits making use of bilateral microinjections of kainic acid (KA) and excitatory amino acid (EAA) receptor antagonists. KA microinjections into either the ...
Pantović R - - 2005
Determination of functional and biochemical parameters as well as the effect of specific therapies on these parameters, in the experimental model of neurotrauma in rabbits. To assess the effect of indomethacin (0.1-3.0 mg/kg for 9 days), a potent inhibitor of endogenous prostaglandin synthesis, on the motor activity and on the ...
Inden Masatoshi - - 2005
Serofendic acid was recently identified as a neuroprotective factor from fetal calf serum. This study was designed to evaluate the neuroprotective effects of an intranigral microinjection of serofendic acid based on behavioral, neurochemical and histochemical studies in hemi-parkinsonian rats using 6-hydroxydopamine (6-OHDA). Rats were injected with 6-OHDA in the presence ...
Patil Sachin - - 2005
Epidemiological studies suggest that high fat diets significantly increase the risk of Alzheimer's disease (AD). In addition, the AD brain is characterized by high fatty acid content compared to that of healthy subjects. Nevertheless, the basic mechanism relating elevated fatty acids and the pathogenesis of AD remains unclear. The present ...
Hartai Z - - 2005
Objective--Excitatory amino acid receptors are involved in the normal physiology of the brain, and may play a role in the pathogenesis of neurological disorders such as Huntington's disease, Parkinson's disease, amyotrophic lateral sclerosis, etc. It has been demonstrated that the blockade of one of these receptors ameliorates the symptoms of ...
Levin Edward D - - 2005
To investigate the behavioral effects of prenatal exposure to the marine toxin domoic acid, pregnant female rats were injected subcutaneously with 0, 0.3, 0.6, or 1.2 mg/kg of domoic acid on gestational day 13. The offspring were then run through a behavioral testing battery to determine the developmental effects of ...
Stazka Janusz - - 2005
Increased serum level of homocysteine is an independent risk factor for vascular disease. The effect of DL-homocysteine on the endothelial production of kynurenic acid, an antagonist of alpha7-nicotinic and N-methyl-D-aspartate (NMDA) glutamate receptors, has been evaluated in vitro and in vivo. In rat aortic rings, DL-homocysteine at 40-100 microM enhanced, ...
Sok D-E - - 2006
BACKGROUND: Reactive oxygen radicals have been implicated in the pathophysiology of many neurologic disorders and brain dysfunctions. Kainic acid has been used as a model agent for the study of neurotoxicity of various excitatory amino acids, since it induces neuronal damage through excessive production of reactive oxygen species. Petasites japonicus ...
Fuchs Sabine A - - 2005
Recent evidence has shown that d-amino acids are present in animals and humans in high concentrations and fulfill specific biological functions. In the central nervous system, two d-amino acids, d-serine and d-aspartate, occur in considerable concentrations. d-Serine is synthesized and metabolized endogenously and the same might account for d-aspartate. d-Serine ...
Okada Junichi - - 2005
Polychlorinated biphenyls (PCBs) are known as environmental pollutants that may cause adverse health problems. However, little is known about the effects of PCBs on acid-sensitive neurons of the medulla oblongata, which regulate respiration. Therefore, the present study was designed to examine whether PCB alters acid-sensitivity of cultured neurons derived from ...
Boldyrev A A - - 2005
Short-term incubation of lymphocytes with homocysteine or its oxidation product homocysteinic acid increased the formation of reactive oxygen species and cell necrosis (in case of homocysteinic acid). Effective concentration of homocysteine and homocysteinic acid (500 microM) significantly surpassed the level observed during hyperhomocysteinemia. The addition of homocysteinic acid in a ...
Kimelberg Harold K - - 2005
In this viewpoint article, I summarize data showing that the astrocytic swelling that occurs early after the acute CNS pathologies ischemia and traumatic brain injury is damaging. We have proposed that one reason may be the release of excitatory amino acids (EAA) via volume-activated anion channels (VRACs) that are activated ...
Mentis George Z - - 2005
Mammalian spinal motoneurons are considered to be output elements of the spinal cord that generate exclusively cholinergic actions on Renshaw cells, their intraspinal synaptic targets. Here, we show that antidromic stimulation of motor axons evokes depolarizing monosynaptic potentials in Renshaw cells that are depressed, but not abolished, by cholinergic antagonists. ...
Woitzik Johannes - - 2005
BACKGROUND: The activity of the hypothalamic gonadotrophin-releasing hormone (GnRH) pulse generator is diminished in uraemia. Since GnRH release is influenced by nitric oxide (NO) neurotransmission, we examined the integrity of hypothalamic NO neurotransmission in the chronically uraemic rat model. METHODS: Adult male castrated rats were rendered uraemic by two-stage 5/6 ...
Nishijima Saori - - 2005
PURPOSE: We examined the mechanism involved in the inhibition of bladder activity in rats by stimulating the rostral pontine reticular formation (RPRF) using carbachol, flavoxate and propiverine, and by analysis of amino acid levels in the lumbosacral cord. MATERIALS AND METHODS: A total of 82 female rats were anesthetized with ...
Lian Xiao-Yuan - - 2005
To test the proposed neuroprotective activity of whole ginseng extract and its components, we used 3-nitropropionic acid (3-NP), an inhibitor of succinate dehydrogenase, to produce neurodegeneration. Treatment with 3-nitropropionic acid (90 mg/kg) over a 5-day period resulted in severe impairment of movement and loss of neurons in the striatum. Pretreatment ...
Robotka Hermina - - 2005
The metabolism of tryptophan along the kynurenine pathway yields several neuroactive intermediates, including kynurenic acid, which is one of the few known endogenous N-methyl-d-aspartate receptor inhibitors; in parallel with this, it is an alpha7 nicotinic acetylcholinergic receptor antagonist. On the basis of these properties, kynurenic acid might therefore come into ...
Hinoi Eiichi - - 2005
The L-glutamate (Glu) has been hypothesized as an excitatory amino acid neurotransmitter in the mammalian central nervous system after successful cloning and identification of a number of genes encoding signaling machineries required for the neurocrine at synapses in the brain. These include excitatory amino acid transporters (EAATs) for signal termination ...
Montiel T - - 2005
The extracellular concentration of glutamate is highly regulated by transporter proteins, due to its neurotoxic properties. Dysfunction or reverse activation of these transporters is related to the extracellular accumulation of excitatory amino acids and neuronal damage associated with ischemia and hypoglycemia. We have investigated by microdialysis the effects of the ...
Zhu Yuan - - 2005
There is increasing evidence showing the involvement of unsaturated free fatty acids in cell death pathways, particularly in the context of apoptotic signalling. Our previous in vitro study has demonstrated that oleic acid, a monounsaturated fatty acid, reduces phosphorylation of proapoptotic Bad through activation of protein phosphatase type 2Cbeta. In ...
Kato Hiroyuki - - 2004
We examined the neuroprotective effects of a novel astrocyte-modulating agent, arundic acid (ONO-2506), in a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) mouse model of Parkinson's disease. Male C57BL/6 mice received four intraperitoneal injections of MPTP (20 mg/kg) at 2 h intervals. Dopamine content in the striatum was reduced to 21% of the normal control ...
Kekesi Gabriella - - 2004
Adenosine, agmatine and kynurenic acid are endogenous ligands acting on different (e.g. adenosine, NMDA, alpha(2)-adrenergic and imidazoline) receptors with a potential role in nociception at the spinal level. Their antinociceptive effects have already been investigated as monotherapy, but only a few studies have reported on their effects on the potency ...
Ahmad Shagufta - - 2004
The antiepileptic drug lamotrigine (LTG) is a relatively novel anticonvulsant frequently used in polytherapy and increasingly in monotherapy. LTG is believed to act by reducing excitatory glutamate (GLU) release due to an inhibition of Na(+) channels. In the present study, we have investigated the effects of acute and chronic (up ...
Reinhard John F JF - - 2004
The amino acid tryptophan is a precursor for the neurotransmitter serotonin as well as for kynurenic and quinolinic acids. These latter molecules are antagonists and agonists, respectively, of the excitatory amino acid glutamate and arise through the kynurenine pathway of tryptophan metabolism. Significant differences exist in the sites and physiological ...
Ilhan Atilla - - 2004
Since overexcitation of excitatory amino acid is an important mechanism in seizure genesis wherein free radicals have recently been suggested to play a critical role, we explored the effects of caffeic acid phenethyl ester (CAPE) administration in pentylenetetrazole (PTZ)-induced seizure in mice. CAPE prevents the oxidative damage in brain tissue ...
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