Search results for "Ley"
showing 10 items of 1218 documents
Organotypic rat cerebellar slice culture as a model to analyze the molecular pharmacology of GABAA receptors
2002
The preservation of the neuronal circuitry in rat cerebellar slice cultures provides an advantage in monitoring the development and characterizing the pharmacology of GABA(A) receptor subtypes. Sprague-Dawley rats, 8-11 days of age, were decapitated, their cerebella were cut into 400-microm slices and transferred into culture dishes. Cell viability and organotypic cerebellar organization of the culture remained well preserved up to 3 weeks. Autoradiographic procedures were introduced in these advanced culture technique and employed [(3)H]Ro 15-4513 in the absence and presence of 10 microM diazepam to visualize all benzodiazepine (BZD) and diazepam-insensitive (DIS) binding sites, respective…
Inhibition of rapid heat responses in nociceptive primary sensory neurons of rats by vanilloid receptor antagonists.
1999
Recent studies demonstrated that heat-sensitive nociceptive primary sensory neurons respond to the vanilloid receptor (VR) agonist capsaicin, and the first cloned VR is a heat-sensitive ion channel. Therefore we studied to what extent heat-evoked currents in nociceptive dorsal root ganglion (DRG) neurons can be attributed to the activation of native vanilloid receptors. Heat-evoked currents were investigated in 89 neurons acutely dissociated from adult rat DRGs as models for their own terminals using the whole cell patch-clamp technique. Locally applied heated extracellular solution (effective temperature ∼53°C) rapidly activated reversible and reproducible inward currents in 80% (62/80) o…
Selective activation of 5-HT(2C) receptors stimulates GABA-ergic function in the rat substantia nigra pars reticulata: a combined in vivo electrophys…
2007
In vivo electrophysiology and microdialysis were used to investigate the physiological role of 5-HT(2C) receptors in the control of substantia nigra pars reticulata (SNr) function. Extracellular single-unit recordings were performed from putative GABA-containing neurons in the SNr of anesthetized rats, and local GABA release was studied by in vivo microdialysis in the SNr of awake freely-moving rats. Systemic administration of the selective 5-HT(2C) receptor agonist (S)-2-(chloro-5-fluoro-indol-1-yl)-1-methylethylamine 1:1 C(4)H(4)O(4) (RO 60-0175) caused a dose-dependent excitation of about 30% of the SNr neurons recorded. However, the remaining neurons were either inhibited or unaffected …
High dose of 8-OH-DPAT decreases maximal dentate gyrus activation and facilitates granular cell plasticity in vivo.
2013
Although several studies have emphasized a crucial role for the serotonergic system in the control of hippocampal excitability, the role of serotonin (5-HT) and its receptors in normal and pathologic conditions, such as temporal lobe epilepsy (TLE), is still unclear. The present study was therefore designed firstly to investigate the acute effect of 8-OH-DPAT, a mixed 5-HT1A/7 receptor agonist, at a high dose (1 mg/kg, i.p.) known to have antiepileptic properties, in a model of acute partial epilepsy in rats. For this purpose, a maximal dentate activation (MDA) protocol was used to measure electrographic seizure onset and duration. In addition, the effect of 8-OH-DPAT on in vivo dentate gyr…
The response to isoproterenol of synaptic ribbon numbers in the rat pineal gland changes during postnatal development
1995
Abstract In the mammalian pineal gland synaptic ribbons (SRs) are dynamic organelles of pinealocytes undergoing a day/night rhythm, with small numbers during daytime and significantly higher numbers at night, similar to the formation of the pineal hormone melatonin. Whereas the day/night rhythm of melatonin synthesis is adrenergically regulated, data on the adrenergic regulation of SR numbers in the rat pineal gland are at variance. While some authors have demonstrated that isoproterenol (ISO) stimulates SR numbers, others could not find any effect. To clarify the issue, we carried out identical experiments in two age groups. It was found that in male Sprague-Dawley rats, administration of …
Moderate drinking? Alcohol consumption significantly decreases neurogenesis in the adult hippocampus
2012
Drinking alcohol in moderation is often considered a health-conscious behavior, associated with improved cardiovascular and brain health. However, “moderate” amounts of alcohol include drinking 3-4 alcohol beverages in a day, which is closer to binge drinking and may do more harm than good. Here we examined how daily drinking of moderate-high alcohol alters the production of new neurons in the adult hippocampus. Male and female adult Sprague-Dawley rats were provided free access to a liquid replacement diet that was supplemented with either 4 % ethanol or Maltodextrin for a period of two weeks. Proliferating cells were labeled with 5-bromo-2-deoxyuridine (BrdU) and the number of BrdU-positi…
Constitutive expression and inducibility of O6-methylguanine-DNA methyltransferase and N-methylpurine-DNA glycosylase in rat liver cells exhibiting d…
1995
AbstractWe have analyzed the expression of the DNA repair genes O6-methylguanine-DNA methyltransferase (MGMT) and N-methylpurine-DNA glycosylase (MPG) at RNA and protein activity level in primary rat hepatocytes in vitro and various rat hepatoma cell lines exhibiting different status of differentiation. The basal level of MGMT mRNA and activity correlated well with the degree of differentiation, as measured by tyrosine aminotransferase (TAT) mRNA expression. Induction of MGMT mRNA and protein activity by X-ray and Nmethyl-N′-nitro-N-nitrosoguanidine (MNNG) treatment was most pronounced in the well-differentiated hepatocytes and in various differentiated hepatoma cell lines (up to 6-fold). T…
Metabolism of tresperimus by rat aorta semicarbazide-sensitive amine oxidase (SSAO).
2002
Tresperimus (Cellimis), a new immunosuppressive agent, is mainly eliminated in the rat through metabolism, in which the oxidative deamination of the primary amine of the drug plays a major role. We have previously demonstrated in vivo the significant involvement of semicarbazide-sensitive amine oxidase (SSAO) in this reaction. Rat aorta, a tissue with one of the highest specific SSAO activities, was tested as a new in vitro model to elucidate tresperimus metabolism, using a combination of liquid chromatography/mass spectrometry (LC/MS) and high-performance liquid chromatography (HPLC) analyses. The metabolites resulting from the main metabolic pathway of the drug were formed in rat aorta ho…
Expression and developmental regulation of the cystine/glutamate exchanger (xc-) in the rat.
2007
The cystine/glutamate exchanger (antiporter x c − ) is a membrane transporter involved in the uptake of cystine, the rate-limiting amino acid in the synthesis of glutathione. Recent studies suggest that the antiporter plays a role in the slow oxidative excitotoxity and in the pathological effects of β-N-oxalylamino-l-alanine, the molecule responsible for neurolathyrism, a neurotoxic upper motor neuron disease. The mouse cystine/glutamate exchanger has been cloned and showed to be composed of two distinct proteins, one of which being a novel protein, named xCT, of 502 amino acids and 12 putative trans-membrane domains. We have generated and purified a polyclonal antibody to mouse xCT and stu…
Different electrophysiological actions of 24- and 72-hour aggregated amyloid-beta oligomers on hippocampal field population spike in both anesthetize…
2010
Diffusible oligomeric assemblies of the amyloid beta-protein (Abeta) could be the primary factor in the pathogenic pathway leading to Alzheimer's disease (AD). Converging lines of evidence support the notion that AD begins with subtle alterations in synaptic efficacy, prior to the occurrence of extensive neuronal degeneration. Recently, however, a shared or overlapping pathogenesis for AD and epileptic seizures occurred as aberrant neuronal hyperexcitability, as well as nonconvulsive seizure activity were found in several different APP transgenic mouse lines. This generated a renewed attention to the well-known comorbidity of AD and epilepsy and interest in how Abeta oligomers influence neu…