Search results for "cortex"
showing 10 items of 1827 documents
The nicotinic acetylcholine receptor agonist (±)-epibatidine increases FGF-2 mRNA and protein levels in the rat brain
2000
Abstract In a previous work, we showed that acute intermittent nicotine treatment up-regulates the level of fibroblast growth factor-2 (FGF-2) mRNA in brain regions of tel- and mesencephalon of rats suggesting that neuroprotective effect of (−)nicotine may, at least in part, involve an activation of the neuronal FGF-2 signalling. The present experiments were designed to extend the study on the nicotinic receptor mediated up-regulation of FGF-2 mRNA levels to the use of the potent nicotinic acetylcholine receptor (nAChR) agonist (±)-epibatidine. The (±)-epibatidine treatment led to a strong and long lasting up-regulation of FGF-2 mRNA expression in the cerebral cortex, in the hippocampal for…
Pharmacokinetic evaluation of mycophenolate mofetil for pemphigus.
2011
Introduction: Pemphigus is an autoimmune blistering disease of the skin and mucous membranes characterized by the development of autoantibodies against the desmosomal proteins, desmoglein-1 and -3. Before the advent of corticosteroids, therapy was almost fatal. The introduction of high-dose corticosteroid therapy has reduced mortality rates to similar to 10%, but long-term use of steroids can lead to side effects, many of which are severe and associated with significant morbidity. Thus, the major goal of pemphigus therapy has been to reduce the patient's cumulative exposure to systemic corticosteroids. Over the last 2 decades, a range of corticosteroid-sparing immunosuppressive agents have …
Update on the principles and novel local and systemic therapies for the treatment of non-infectious uveitis.
2012
Ocular inflammatory disorders constitute a sight-threatening group of diseases that might be managed according to their severity. Their treatment guidelines experience constant changes with new agents that improve the results obtained with former drugs. Nowadays we can make use of a five step protocol in which topical, periocular and systemic corticosteroids remain as the main therapy for non-infectious uveitis. In addition, immunosuppresive drugs can be added in order to enhance the anti-inflammatory effects and to play the role of corticosteroid-sparing agents. These can be organized in four other steps: cyclosporine and methotrexate in a second one; azathioprine, mycophenolate and tacrol…
Cortical and subcortical visual event-related potentials to oddball stimuli in rabbits
2000
We applied repetitive transcranial magnetic stimulation (rTMS) in order to induce interference on visuo-spatial perception in 11 healthy subjects. Subjects performed a visuo-spatial task requiring judgements about the symmetry of prebisected lines. Visual stimuli consisted of symmetrically or asymmetrically transected lines, tachystoscopically presented for 50 ms on a computer-monitor. Performance was examined in basal condition and during rTMS trains of 10 stimuli at 25 Hz, delivered through a focal coil over right or left posterior parietal cortex (P5 and P6 sites) and triggered synchronously with visual stimulus. Randomly intermixed sham rTMS trains were employed to control for non-speci…
Voluntary and Involuntary Attention in Bistable Visual Perception: A MEG Study
2020
In this study, voluntary and involuntary visual attention focused on different interpretations of a bistable image, were investigated using magnetoencephalography (MEG). A Necker cube with sinusoidally modulated pixels' intensity in the front and rear faces with frequencies 6.67 Hz (60/9) and 8.57 Hz (60/7), respectively, was presented to 12 healthy volunteers, who interpreted the cube as either left- or right-oriented. The tags of these frequencies and their second harmonics were identified in the average Fourier spectra of the MEG data recorded from the visual cortex. In the first part of the experiment, the subjects were asked to voluntarily control their attention by interpreting the cu…
Intrinsic activation of GABAA receptors suppresses epileptiform activity in the cerebral cortex of immature mice
2010
SUMMARY Purpose: Activation of ionotropic c-aminobutyric acid type A (GABAA) receptors induces in immature neocortical neurons a membrane depolarization that may contribute to the higher epilepsy susceptibility in newborns. To elucidate whether depolarizing GABAergic responses enhance or attenuate epileptiform activity in the immature neocortex, we investigated the effect of agonists, antagonists, and positive modulators of GABAA receptors on epileptiform activity. Methods: We performed in vitro field potential recordings on isolated whole neocortex preparations and whole cell recordings of identified pyramidal neurons in 400-lm slices of immature (postnatal day 1–7) mice. Epileptiform acti…
Effects of High Frequency Repetitive Transcranial Magnetic Stimulation (HF-rTMS) on Delay Discounting in Major Depressive Disorder: An Open-Label Unc…
2019
Background: Delay discounting (DD) refers to the decrease of a present subjective value of a future reward as the delay of its delivery increases. Major depressive disorder (MDD), besides core emotional and physical symptoms, involves difficulties in reward processing. Depressed patients often display greater temporal discounting rates than healthy subjects. Repetitive transcranial magnetic stimulation (rTMS) is a non-invasive brain stimulation technique applied in several countries to adult patients with treatment resistant depression. Studies suggest that this technique can be used to modulate DD, but no trial has assessed its effects on depressed patients. Methods: In this open-label unc…
Auditory cortical and hippocampal local-field potentials to frequency deviant tones in urethane-anesthetized rats: An unexpected role of the sound fr…
2015
Abstract The human brain can automatically detect auditory changes, as indexed by the mismatch negativity of event-related potentials. The mechanisms that underlie this response are poorly understood. We recorded primary auditory cortical and hippocampal (dentate gyrus, CA1) local-field potentials to serial tones in urethane-anesthetized rats. In an oddball condition, a rare (deviant) tone ( p = 0.11) randomly replaced a repeated (standard) tone. The deviant tone was either lower (2200, 2700, 3200, 3700 Hz) or higher (4300, 4800, 5300, 5800 Hz) in frequency than the standard tone (4000 Hz). In an equiprobability control condition, all nine tones were presented at random ( p = 0.11). Diffe…
Increased synthesis of nitric oxide in rat brain cortex due to halogenated volatile anesthetics confirmed by EPR spectroscopy
2002
Background: Halogenated volatile anesthetics (HVAs) are considered to be inhibitors of nitric oxide synthase (NOS). On other hand, NO mediates the vasodilation produced by HVAs. Thus, both increase and decrease of NO concentration in brain tissues are possible during anesthesia. Previously, we have observed an increase of NO content in rat brain cortex under halothane anesthesia. The goal of this study was to determine whether the observed phenomenon was general for this anesthetic group, if it was specific for brain cortex, and if the NO increase was due changes in NOS activity. Methods: NO scavengers were injected to adult rats 30 min prior to anesthesia. Rats were anesthetized by inhalat…