Search results for "ocular"
showing 10 items of 1219 documents
AAV vector-mediated overexpression of CB1 cannabinoid receptor in pyramidal neurons of the hippocampus protects against seizure-induced excitoxicity.
2010
The CB1 cannabinoid receptor is the most abundant G-protein coupled receptor in the brain and a key regulator of neuronal excitability. There is strong evidence that CB1 receptor on glutamatergic hippocampal neurons is beneficial to alleviate epileptiform seizures in mouse and man. Therefore, we hypothesized that experimentally increased CB1 gene dosage in principal neurons would have therapeutic effects in kainic acid (KA)-induced hippocampal pathogenesis. Here, we show that virus-mediated conditional overexpression of CB1 receptor in pyramidal and mossy cells of the hippocampus is neuroprotective and moderates convulsions in the acute KA seizure model in mice. We introduce a recombinant a…
Polysialic acid is required for dopamine D2 receptor-mediated plasticity involving inhibitory circuits of the rat medial prefrontal cortex.
2011
Decreased expression of dopamine D2 receptors (D2R), dysfunction of inhibitory neurotransmission and impairments in the structure and connectivity of neurons in the medial prefrontal cortex (mPFC) are involved in the pathogenesis of schizophrenia and major depression, but the relationship between these changes remains unclear. The polysialylated form of the neural cell adhesion molecule (PSA-NCAM), a plasticity-related molecule, may serve as a link. This molecule is expressed in cortical interneurons and dopamine, via D2R, modulates its expression in parallel to that of proteins related to synapses and inhibitory neurotransmission, suggesting that D2R-targeted antipsychotics/antidepressants…
The subplate and early cortical circuits.
2010
The developing mammalian cerebral cortex contains a distinct class of cells, subplate neurons (SPns), that play an important role during early development. SPns are the first neurons to be generated in the cerebral cortex, they reside in the cortical white matter, and they are the first to mature physiologically. SPns receive thalamic and neuromodulatory inputs and project into the developing cortical plate, mostly to layer 4. Thus SPns form one of the first functional cortical circuits and are required to relay early oscillatory activity into the developing cortical plate. Pathophysiological impairment or removal of SPns profoundly affects functional cortical development. SPn removal in v…
Variance Thresholded EMD-CCA Technique for Fast Eye Blink Artifacts Removal in EEG
2017
International audience; Eye blink (EB) artifacts generated during eye blinks often contaminate electroencephalogram (EEG) signal. Previously Empirical Mode Decomposition (EMD) and Canonical Correlation Analysis (CCA), hybrid EMD-CCA were developed for EB artifact removal in EEG. However, EMD restricts the hybrid algorithm for real time implementation due to its slow processing nature, hence the algorithm has to be enhanced so that it can be a viable solution for real-time EB artifact removal. In this research work, to avoid applying EMD repetitively as and when EB artifacts occur, a method to use EMD minimally is approached. A suitable EB artifact region is detected through a variance thres…
Long-Term Potentiation in the Recurrent Inhibitory Circuit of the Dentate Gyrus
1988
The question of whether long-term potentiation occurs in the inhibitory circuits of the hippocampus remains controversial. Buszaki and Eidelberg (1982), recording extracellularly from putative interneurones (basket cells) in the dentate gyrus and area CAl of the anaesthetized rat, found a prolonged increase in probability of cell firing to afferent stimulation after high-frequency stimulation of Schaffer-commissural fibres, and concluded that LTP occurs at excitatory feedforward synapses onto interneurones. Similarly, Kairis et al (1987) have presented field potential evidence for LTP in feedforward synapses onto inhibitory neurones in the dentate gyrus of the anaesthetized rat. In the hipp…
Retrobulbäre Bestrahlung bei endokriner Orbitopathie - Erfahrungen im Langzeitverlauf
2002
Background Significance of retrobulbar irradiation in patients suffering form Graves' ophthalmopathy, though established since almost one century, is subject of scientific debate. The present study investigated the effect of retrobulbar irradiation using a standardized protocol focussing on long term results. Patients and methods Between 1981 and 1997, 104 patients treated by retrobulbar irradiation (10 to 20 Gray) due to Graves' disease. Twenty-nine of these underwent irradiation as sole treatment (mean follow-up 57 months), while in the remaining 75, it was combined with a systemic steroid treatment (mean follow-up 40 months). Patients were evaluated regarding proptosis, intraocular press…
Suprachoroidal Bleeding After XEN Gel Implantation
2017
Purpose To report for the first time a clinical case of suprachoroidal bleeding after XEN45 gel implantation. Observations A 84-year old female patient with pseudoexfoliation glaucoma with intraocular pressure (IOP) (20 mm Hg) above target despite maximal IOP-lowering therapy was scheduled for XEN45 gel implantation. The XEN45 gel implantation went without complications and was properly placed in the anterior chamber and beneath the conjunctiva. On the first postoperative day, the patient presented with an IOP of 4 mm Hg, a functioning bleb and a deep anterior chamber. On the second day she developed suprachoroidal bleeding. A wait and see strategy was followed and the patient monitored ste…
Vascular resistance arm of the baroreflex: methodology and comparison with the cardiac chronotropic arm.
2020
Baroreflex response consists of cardiac chronotropic (effect on heart rate), cardiac inotropic (on contractility), venous (on venous return) and vascular (on vascular resistance) arms. Because of its measurement simplicity, cardiac chronotropic arm is most often analysed. The aim was to introduce a method to assess vascular baroreflex arm, and to characterize its changes during stress. We evaluated the effect of orthostasis and mental arithmetics (MA) in 39 (22 female, median age: 18.7 yrs.) and 36 (21 female, 19.2 yrs.) healthy volunteers, respectively. We recorded systolic and mean blood pressure (SBP and MBP) by volume-clamp method and R-R interval (RR) by ECG. Cardiac output (CO) was re…
The ocular manifestations in IBD screening (OMIS) questionnaire: pilot study on detection of ocular involvement in inflammatory bowel diseases.
2020
Purpose: To assess the usefulness of a dedicated questionnaire for patients with inflammatory bowel diseases (IBD) treated with biological drugs for the detection of ocular extraintestinal manifestations (EIMs). IBD can cause extraintestinal symptoms including ocular complaints which are frequently ignored and may be associated with significant morbidity, including blindness. Methods: We developed a questionnaire, named Ocular Manifestations in IBD Screening (OMIS) questionnaire, after agreement between gastroenterologists and ophthalmologists. The questionnaire was administered by a non-ophthalmologist physician to 96 IBD patients treated with biological drugs. Results: 35 patients (36.5%)…
Stereopsis assessment at multiple distances with an iPad application
2017
[EN] We present a new application for iPad for screening stereopsis at multiple distances that allows testing up to ten levels of stereoacuity at each distance. Our approach is based on a random dot stereogram viewable with anaglyph spectacles. Sixty-five subjects with no ocular diseases, wearing their habitual correction were measured at 3 m and 0.5 m. Results were compared with a standard stereoscopic test (TNO). We found not statistically significant differences between both tests, but our method achieved higher reproducibility. Applications in visual screening programs and to design and use of 3D displays, are suggested. (C) 2017 Elsevier B.V. All rights reserved.