Search results for "ULB"
showing 10 items of 219 documents
Long-term habituation to spatial novelty in blind cave fish (Astyanax hubbsi): role of the telencephalon and its subregions.
2000
Blind cave fish, when released into a novel environment, show a typical exploratory behavior characterized by high swim speed along walls shortly after release. This behavior wanes during prolonged exposure and thus may reflect habituation to novelty. As the hippocampus of mammals, which plays a crucial role in spatial learning, is part of the telencephalon, the possible involvement of this brain structure of fish was investigated in exploratory behavior. Ablation of the whole telencephalon or bilateral removal of dorsal parts of the hemispheres reduced activity; in contrast, unilateral lesions of one hemisphere, bilateral lesions of dorsal and dorsoventral parts, and removal of olfactory b…
Olfactory discrimination ability and brain expression of c-fos, Gir and Glut1 mRNA are altered in n-3 fatty acid-depleted rats
2007
Abstract The long-chain polyunsaturated n − 3 fatty acids ( n − 3 PUFA), particularly docosahexaenoic acid (DHA), are abundantly present in the central nervous system and play an important role in cognitive functions such as learning and memory. We, therefore, investigated the effects of n − 3 PUFA-depletion in rats (F2 generation) on the learning of an olfactory discrimination task, progressively acquired within a four-arm maze, and on the mRNA expression of some candidate genes, i.e., c-fos, Gir and glucose transporter (Glut1), which could reflect the level of cerebral activity. We observed that DHA contents were dramatically decreased in the olfactory bulb, the piriform cortex and the…
Characterization of a population of tyrosine hydroxylase-containing interneurons in the external plexiform layer of the rat olfactory bulb
2012
The olfactory bulb (OB) of mammals contains the major endogenous dopamine-producing system in the forebrain. The vast majority of dopaminergic neurons consists of juxtaglomerular cells, which innervate the olfactory glomeruli and modulate the entrance of sensory information to the OB. Although dopaminergic juxtaglomerular cells have been widely investigated, the presence of dopaminergic interneurons other than juxtaglomerular cells has been largely unexplored. In this study, we analyze a population of tyrosine hydroxylase (TH)-containing interneurons located in the external plexiform layer (EPL) of the rat OB. These interneurons are GABAergic and morphologically heterogeneous. They have an …
Expression and differential localization of xenobiotic transporters in the rat olfactory neuro-epithelium.
2011
International audience; Transporters, such as multidrug resistance P-glycoproteins (MDR), multidrug resistance-related proteins (MRP) and organic anion transporters (OATs), are involved in xenobiotic metabolism, particularly the cellular uptake or efflux of xenobiotics (and endobiotics) or their metabolites. The olfactory epithelium is exposed to both inhaled xenobiotics and those coming from systemic circulation. This tissue has been described as a pathway for xenobiotics to the brain via olfactory perineural space. Thereby, olfactory transporters and xenobiotic metabolizing enzymes, dedicated to the inactivation and the elimination of xenobiotics, have been involved in the toxicological p…
Subventricular zone localized irradiation affects the generation of proliferating neural precursor cells and the migration of neuroblasts
2012
Radiation therapy is a part of the standard treatment for brain tumor patients, often resulting in irreversible neuropsychological deficits. These deficits may be due to permanent damage to the neural stem cell (NSC) niche, damage to local neural progenitors, or neurotoxicity. Using a computed tomography-guided localized radiation technique, we studied the effects of radiation on NSC proliferation and neuroblast migration in the mouse brain. Localized irradiation of the subventricular zone (SVZ) eliminated the proliferating neural precursor cells and migrating neuroblasts. After irradiation, type B cells in the SVZ lacked the ability to generate migrating neuroblasts. Neuroblasts from the u…
Vasoactive intestinal polypeptide-containing elements in the olfactory bulb of the hedgehog (Erinaceus europaeus).
2002
Abstract The distribution of vasoactive intestinal polypeptide (VIP)-immunopositive elements was analyzed in the olfactory bulb (OB) of the Western European hedgehog (Erinaceus europaeus) under light and electron microscopy. The immunoreactivity appeared in an abundant population of periglomerular cells of the glomerular layer, in interneurons of the external plexiform layer, and in a restricted group of deep short-axon cells of the internal plexiform layer, the granule cell layer and the white matter. In the glomerular layer, VIP-containing periglomerular cells constituted a population of non-GABAergic neurons and did not receive synapses from olfactory axons. In the EPL, VIP-immunoreactiv…
α4-1 Subunit mRNA of the nicotinic acetylcholine receptor in the rat olfactory bulb: cellular expression in adult, pre- and postnatal stages
1996
In addition to their role in signal transduction, nicotinic acetylcholine receptors have been shown in vi-tro to be involved in neuronal growth cone regulation during development. This idea is supported by recent histochemical findings showing that iso- and archicortical nicotinic alpha4-1 receptor mRNA expression precedes cholinergic fiber ingrowth. To test whether this also holds true for rhinencephalic parts of the telencephalon, we have studied the olfactory bulb by digoxigenin-mediated in situ hybridization, using an alpha4-1 isoform-specific riboprobe and an alkaline-phosphatase-based detection system. Development is characterized by early intense alpha4-1 mRNA expression (embryonic d…
Dysarthria and lacunar stroke
1996
We investigated the supranuclear tracts involved in speech production in 8 patients with dysarthria associated with a single lacunar stroke.Magnetic resonance imaging revealed the lesion site in 7 out of 8 patients. We tested corticobulbar tract function using transcranial magnetic stimulation and demonstrated impairment of the corticolingual projections in all the patients and in 5 patients impairment of the corticofacial projections. Sensory function in the oral cavity was impaired in 1 out of 8 patients.99m Tc hexamethyl-propylene amine oxime-single-photon emission computerized tomography (HMPAO-SPECT) imaging, performed in 5 patients, showed cerebellar diaschisis in 1, suggesting additi…
Mating Increases Neuronal Tyrosine Hydroxylase Expression and Selectively Gates Transmission of Male Chemosensory Information in Female Mice
2013
Exposure to chemosensory signals from unfamiliar males can terminate pregnancy in recently mated female mice. The number of tyrosine hydroxylase-positive neurons in the main olfactory bulb has been found to increase following mating and has been implicated in preventing male-induced pregnancy block during the post-implantation period. In contrast, pre-implantation pregnancy block is mediated by the vomeronasal system, and is thought to be prevented by selective inhibition of the mate's pregnancy blocking chemosignals, at the level of the accessory olfactory bulb. The objectives of this study were firstly to identify the level of the vomeronasal pathway at which selective inhibition of the m…
Oculoectodermal syndrome: Report of a new case with a broad clinical spectrum
2014
Oculoectodermal syndrome (OMIM 600268) is rare and characterized by aplasia cutis congenita, epibulbar dermoids, and other abnormalities. We report herein on a newly recognized patient with oculoectodermal syndrome, which is the 19th reported patient with OES. The boy aged six years demonstrated a broad clinical spectrum of this condition, including aplasia cutis congenita, epibulbar dermoids, hyperkeratotic papule, mildly enlarged cisterna magna, and an enlarged fluid space in the quadrigeminal cistern, suggesting a cyst. He also manifested anomalies not reported associated with this disorder, including systematized epidermal nevus following Blaschko's lines, hypopigmented skin lesions, an…