Search results for "GLUTAMATE"
showing 10 items of 434 documents
Ursodeoxycholic acid protects against secondary biliary cirrhosis in rats by preventing mitochondrial oxidative stress
2004
Ursodeoxycholic acid (UDCA) improves clinical and biochemical indices in primary biliary cirrhosis and prolongs survival free of liver transplantation. Recently, it was suggested that the cytoprotective mechanisms of UDCA may be mediated by protection against oxidative stress, which is involved in the development of cirrhosis induced by chronic cholestasis. The aims of the current study were 1) to identify the mechanisms involved in glutathione depletion, oxidative stress, and mitochondrial impairment during biliary cirrhosis induced by chronic cholestasis in rats; and 2) to determine the mechanisms associated with the protective effects of UDCA against secondary biliary cirrhosis. The find…
Role of N-methyl-D-aspartate receptors in the long-term effects of repeated social defeat stress on the rewarding and psychomotor properties of cocai…
2019
Abstract Exposure to social stress increases the vulnerability of experimental animals to the rewarding effects of cocaine and it has been suggested that the glutamatergic system could be involved in these effects of stress. The aim of this work is to determine the role of N-methyl- d -aspartate (NMDA) glutamate receptors in the influence of social stress on the conditioned place preference and locomotor sensitization induced by cocaine. Mice treated with saline or NMDA antagonist memantine (5 or 10 mg/kg) underwent repeated social defeat or were kept in the exploration control condition. After three weeks, all groups (SAL + RSD, M5 + RSD, M10 + RSD, SAL + EXP, M5 + EXP and M10 + EXP) were …
Alzheimer's disease: amino acid levels and brain metabolic status.
2013
Abstract To study brain free amino acids and their relation with dementia we measured, by high-performance liquid chromatography (HPLC), the concentration of eight free amino acids, amines and related compounds. We used temporal cortex (TC) samples obtained from 13 Alzheimer’s disease (AD) patients and an equal number of agematched controls (AC). The patterns of free amino acids, amines and related compounds showed significant quantitative changes in AD conditions with respect to healthy ones. In Alzheimer patients, lower levels of GABA were found in the TC (-57 %). Amino acids glutamate (Glu), and aspartate (Asp) concentrations, also appeared significantly reduced in the TC of AD patients …
NMDA receptor antagonist felbamate reduces behavioral deficits and blood-brain barrier permeability changes after experimental subarachnoid hemorrhag…
2007
Increased levels of glutamate and aspartate have been detected after subarachnoid hemorrhage (SAH) that correlate with neurological status. The NMDA receptor antagonist felbamate (FBM; 2-phenyl-1,3-propanediol dicarbamate) is an anti-epileptic drug that elicits neuroprotective effects in different experimental models of hypoxia-ischemia. The aim of this dose-response study was to evaluate the effect of FBM after experimental SAH in rats on (1) behavioral deficits (employing a battery of assessment tasks days 1-5 post-injury) and (2) blood-brain barrier (BBB) permeability changes (quantifying microvascular alterations according to the extravasation of protein-bound Evans Blue by a spectropho…
Carnitine congener mildronate protects against stress- and haloperidol-induced impairment in memory and brain protein expression in rats.
2014
The present study investigates the efficacy of mildronate, a carnitine congener, to protect stress and haloperidol-induced impairment of memory in rats and the expression of brain protein biomarkers involved in synaptic plasticity, such as brain-derived neurotrophic factor (BDNF), acetylcholine esterase and glutamate decarboxylase 67 (GAD67). Two amnesia models were used: 2h immobilization stress and 3-week haloperidol treatment. Stress caused memory impairment in the passive avoidance test and induced a significant 2-fold BDNF elevation in hippocampal and striatal tissues that was completely inhibited by mildronate. Mildronate decreased the level of GAD67 (but not acetylcholine esterase) e…
Nitric oxide and glutamate interaction in the control of cortical and hippocampal excitability.
1999
Summary: Purpose: We investigated the role of nitric oxide (NO) as a new neurotransmitter in the control of excitability of the hippocampus and the cerebral cortex, as well as the possible functional interaction between NO and the glutamate systems. Methods: The experiments were performed on anesthetized rats. The bioelectrical activities of the somatosensory cortex and the CA1 region of the hippocampus of these rats were recorded. Pharmacologic inhibition of NO synthase (NOS) through the nonselective and brain-selective inhibitors, N-nitro-L-arginine methyl ester (l-NAME) and 7-nitroindazole (7-NI), was performed. Results: The treatments caused the appearance of an interictal discharge act…
Dopamine acting through D2 receptors modulates the expression of PSA-NCAM, a molecule related to neuronal structural plasticity, in the medial prefro…
2008
A "neuroplastic" hypothesis proposes that changes in neuronal structural plasticity may underlie the aetiology of depression and the action of antidepressants. The medial prefrontal cortex (mPFC) is affected by this disorder and shows an intense expression of the polysialylated form of the neural cell adhesion molecule (PSA-NCAM), a plasticity-associated molecule, which is expressed mainly in interneurons. The monoamines serotonin, dopamine and noradrenaline are the principal targets of antidepressant action. Pharmacological manipulation of serotonin levels regulates synaptophysin and PSA-NCAM expression in the adult mPFC. However, the involvement of structural plasticity on the antidepress…
Streptozotocin diabetic mice display depressive-like behavior and alterations in the structure, neurotransmission and plasticity of medial prefrontal…
2015
Diabetes mellitus patients are at increased risk of developing depression, although the neurobiological bases of this comorbidity are not yet fully understood. These patients show CNS alterations, similar to those found in major depression, including changes in the structure and neurotransmission of excitatory neurons. However, although depressive patients and animal models also display alterations in inhibitory networks, little is known about the effects of diabetes on interneurons. Our main objective was to study the impact of diabetes on interneurons of the medial prefrontal cortex (mPFC), one of the regions most affected by major depression. For this purpose we have induced diabetes wit…
Gender-dependent behavioural impairment and brain metabolites in young adult rats after short term exposure to lead acetate
2012
We investigated the behavioural effects of short-term lead (Pb) exposure in adult rats producing blood Pb concentration (<10. μg/dL) below those associated with neurological impairment in occupationally exposed individuals. In order to assess gender differences, we performed parallel behavioural experiments in male and female rats. Exposure to Pb acetate (50. mg/L in drinking water) for 30-45 days induced behavioural alterations consisting in hyperactivity in a novel environment and impairment of spatial memory. These effects were observed only in male rats. Object recognition, motor coordination were unaffected by Pb exposure. Magnetic resonance spectroscopy allows . in vivo assessment of …
Environmental enrichment promotes neurogenesis and changes the extracellular concentrations of glutamate and GABA in the hippocampus of aged rats.
2005
The aim of the present study was to investigate the effects of environmental enrichment on the neurogenesis and the extracellular concentrations of glutamate and GABA in the hippocampus of freely moving young and aged rats. Male Wistar rats of 2 (young) and 25 (old) months of age were housed during 8 weeks in an enriched environment; control rats were kept in individual plastic cages during that same period of time. Rats were injected intraperitoneally with bromodeoxyuridine (BrdU; 40 mg/kg; 7 days) during the fourth week of the housing period to detect neurogenesis in the dentate gyrus (DG) of the hippocampus. Rats were sacrified 6 weeks after the last injection of BrdU. During the last we…