Search results for "Neuron"
showing 10 items of 2611 documents
Hypoosmolar conditions reduce extracellular volume fraction and enhance epileptiform activity in the CA3 region of the immature rat hippocampus
2006
The osmolarity of the extracellular space (ECS) compartment is an important factor determining the excitability of neuronal tissue. In the adult hippocampus an important role of osmolarity and ECS diffusion parameters on the susceptibility to epileptic events is well established, but the influence of hypo- and hyperosmolar conditions on the immature hippocampus remains elusive. To investigate the influence of osmolarity on epileptiform activity, extracellular field potentials were recorded in the CA3 region of hippocampal slices of immature (postnatal days 4-7) Wistar rats. The ECS diffusion parameters were determined by the real-time tetramethylammonium (TMA+) iontophoretic method with ion…
NMDA-induced acetylcholine release in mouse striatum: role of NO synthase isoforms
2002
Striatal cholinergic interneurons are stimulated by glutamatergic inputs from thalamus and cortex via NMDA receptors. The present microdialysis study was designed to characterize the role of nitric oxide (NO) in this process and to identify the NO synthase (NOS) isoform responsible for this effect. For this purpose, we studied the effects of NMDA and 3-morpholino sydnonimine (SIN-1) perfusions on the release of acetylcholine (ACh) in mouse striatum. In wild-type C57/Bl6 mice, perfusion of NMDA (100 µm) induced a two-fold stimulation of ACh release. This effect was attenuated in mice lacking endothelial NOS but was completely absent in mice lacking neuronal NOS. Local perfusion of SIN-1 (300…
Congenital malformations and perinatal morbidity associated with intestinal neuronal dysplasia.
1998
A close relation between different forms of dysganglionosis such as intestinal neuronal dysplasia (IND) type B and aganglionosis has been established. No systematic analysis of other malformations and diseases accompanying IND has been made as yet. Congenital malformations and perinatal morbidity were analyzed in 109 patients with IND seen at the Department of Pediatric Surgery in Mainz from 1977 to 1996. IND was associated with Hirschsprung's disease in 47 cases; 22 children with IND had other abdominal malformations, including anal atresia, rectal stenosis, sigmoidal stenosis, ileal atresia, pyloric stenosis, and esophageal atresia. A cystic bowel duplication, a choledochal cyst, and a pe…
The clinical relevance of non-classified dysganglionoses and implications for a new grading system
2001
In addition to the classified types of dysganglionosis, certain non-classified dysganglionoses (NCD) (types 1-4) were introduced by Meier-Ruge in 1992. Clinical data on these conditions are limited. Among 134 children with intestinal dysganglionoses (ID) treated from 1979 to 1999, 12 were identified to have a NCD. Their clinical course is presented. The existence of mild ID (type 1) is difficult to demonstrate. Current definitions and data on clinical relevance are not convincing. An indication for surgical treatment is not present. Isolated hypogenesis of the submucous plexus (SMP) (type 2, n = 8) is clinically a more severe kind of intestinal neuronal dysplasia type B and often requires e…
Coplanar Indirect-Navigated Intraoperative Ultrasound: Matching Un-navigated Probes With Neuronavigation During Neurosurgical Procedures. How We Do I…
2021
BACKGROUND Intraoperative ultrasound (IOUS) is becoming more and more adopted in neurosurgery, since it has been associated to greater extent of resection (EOR) and to gross total resection (GTR) during brain tumor surgery. IOUS main limitations are spatial resolution, width and orientation of the field of view and scan quality, which are operator-dependent. Furthermore, most neurosurgeons are not confident with this technique, which needs a long learning curve in order to identify and interpret anatomic structures. OBJECTIVE To describe an effective procedure to take advantages of both IOUS and neuronavigation in case of lack of a navigated ultrasound system. METHODS We propose a reliable …
The CB1 cannabinoid receptor mediates excitotoxicity-induced neural progenitor proliferation and neurogenesis.
2007
Endocannabinoids are lipid signaling mediators that exert an important neuromodulatory role and confer neuroprotection in several types of brain injury. Excitotoxicity and stroke can induce neural progenitor (NP) proliferation and differentiation as an attempt of neuroregeneration after damage. Here we investigated the mechanism of hippocampal progenitor cell engagement upon excitotoxicity induced by kainic acid administration and the putative involvement of the CB1 cannabinoid receptor in this process. Adult NPs express kainate receptors that mediate proliferation and neurosphere generation in vitro via CB1 cannabinoid receptors. Similarly, in vivo studies showed that excitotoxicity-induce…
A case of guillain-barre syndrome in a patient with non small cell lung cancer treated with chemotherapy
2006
Guillain-Barré Syndrome (GBS) is a demyelinating polyneuropathy of probable autoimmune pathogenesis characterized by rapidly progressive symmetric paralysis. In the literature some cases of GBS associated with anticancer chemotherapy are reported. We present a case of a 55-year old woman who complained of progressive motor deficit in four limbs, areflexia in lower limbs and facial nerve paralysis one week after beginning cisplatin-gemcitabine chemotherapy for metastatic lung cancer. The cerebrospinal fluid analysis showed a strong positive Pandy reaction with 435 mg/dl total protein. The electromyography and the electroneuronography established the diagnosis of inflammatory demyelinating po…
Serotonergic modulation of hippocampal acetylcholine release after long-term neuronal grafting
2000
Adult female rats sustained aspirative fimbria-fornix lesions and, 2 weeks later, received intrahippocampal grafts of fetal septal or mixed septal-raphe cell suspensions. Twenty-four months later, the extracellular concentration of hippocampal acetylcholine (ACh) was determined by microdialysis. Basal ACh levels (5-65 fmol/5 microl sham-operated rats) were strongly reduced after lesioning (3-7 fmol/5 microl). In septally transplanted and septal-raphe co-transplanted rats, hippocampal ACh concentrations were restored to near-normal levels (15-25 fmol/5 microl), indicating long-term functional survival of hippocampal transplants. After administration of citalopram (100 microM by infusion) and…
PGC-1α: a master gene that is hard to master
2012
Peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α) is a transcriptional coactivator that favorably affects mitochondrial function. This concept is supported by an increasing amount of data including studies in PGC-1α gene-deleted mice, suggesting that PGC-1α is a rescue factor capable of boosting cell metabolism and promoting cell survival. However, this view has now been called into question by a recent study showing that adeno-associated virus-mediated PGC-1α overexpression causes overt cell degeneration in dopaminergic neurons. How is this to be understood, and can these seemingly conflicting findings tell us something about the role of PGC-1α in cell stress and in cont…
Neuronal and extraneuronal uptake and efflux of catecholamines in the isolated rabbit heart
1974
1. Isolated rabbit hearts were perfused with (−)-noradrenaline, (−)-adrenaline and (±)-isoprenaline for various time periods (1–180 min) and then washed with an amine-free medium. The venous concentration of the amine was estimated fluorimetrically during the infusion and after its end, to study removal and efflux, respectively. 2. In untreated hearts and after pretreatment with reserpine the removal had a constant rate over 20–60 min. After pretreatment with pargyline to block monoamine oxidase (MAO), however, the removal of noradrenaline declined exponentially to zero. Inhibition of the neuronal uptake (desipramine) and chemical sympathectomy (6-hydroxydopamine) abolished the removal of n…