Dúplex transcraneal en la enfermedad moyamoya / No disponible

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Neurogenesis in subclasses of vomeronasal sensory neurons in adult mice.

The vomeronasal sensory epithelium contains two distinct populations of vomeronasal sensory neurons. Apical neurons express G(i) (2) (α) -linked V1R vomeronasal receptors and project to the anterior portion of the accessory olfactory bulb, while basal neurons express G(o) (α) -linked V2R receptors and project to the posterior portion. Sensory neurons expressing V1R and V2R vomeronasal receptors are sensitive to different stimuli. Neurons in the vomeronasal system undergo continuous cell turnover during adulthood. To analyze over time neurogenesis of the different sensory cell populations, adult mice were injected with bromodeoxyuridine (BrdU) and sacrificed at postinjection days 1, 3, 5, 7, and 11. Newborn vomeronasal neurons were revealed by antibodies against BrdU while subclasses of vomeronasal neurons were identified using antibodies against G(o) (α) or G(i) (2) (α) proteins. To ascertain whether G proteins are early expressed during neurogenesis, multiple labeling experiments using PSA-NCAM and doublecortin were performed. Distribution of BrdU-labeled cells was analyzed in angular segments from the margin of the sensory epithelium. No sexual differences were found. Within survival groups, BrdU-G(o) (α) labeled cells were found more marginally when compared with BrdU-G(i) (2) (α) labeled cells. The number of BrdU-positive cells decreased from day 1 to day 3 to remain constant afterwards. The relative proportions of BrdU-G(i) (2) (α) and BrdU-G(o) (α) labeled cells remained similar and constant from postinjection day 1 onwards. This rate was also comparable with BrdU-positive cells starting day 3. These results indicate an early, constant, and similar rate of neurogenesis in the two major subclasses of vomeronasal neurons, which suggests that both cell populations maturate independently.

[Non-motor disorders in Parkinson's disease: introduction and general features]. / Trastornos no motores de la enfermedad de Parkinson: introducción y generalidades.

INTRODUCTION: Two hundred years ago James Parkinson accurately described the disease that bears his name today, focusing not only on motor aspects but also on non-motor symptoms suffered by these patients. DEVELOPMENT: Non-motor symptoms are prevalent and decrease the quality of life of the patients with Parkinson's disease. In recent years, some non-motor scales have been developed to avoid the problem of underdiagnosis. Moreover, some of them have been proposed as clinical predictors for Parkinson's disease and it is has been suggested that individuals with any of these non-motor symptoms and without motor manifestations of the disease could be the aim for neuroprotective therapies when they become available. CONCLUSIONS: Non-motor symptoms are prevalent and have a great impact in the quality of life of patients. Therefore, it is important to detect and treat them. Their role as predictors of the disease is unclear yet.

Somatostatin, tau, and beta-amyloid within the anterior olfactory nucleus in Alzheimer disease.

Impaired olfaction is an early symptom of Alzheimer disease (AD). This likely to reflect neurodegenerative processes taking place in basal telencephalic structures that mediate olfactory processing, including the anterior olfactory nucleus. Betaeta-amyloid (Abeta) accumulation in AD brain may relate to decline in somatostatin levels: somatostatin induces the expression of the Abeta-degrading enzyme neprilysin and somatostatin deficiency in AD may therefore reduce Abeta clearance. We have investigated the expression of somatostatin in the anterior olfactory nucleus of AD and control brain. We report that somatostatin levels were reduced by approximately 50% in AD brain. Furthermore, triple-immunofluorescence revealed co-localization of somatostatin expression with Abeta (65.43%) with Abeta and tau (19.75%) and with tau (2.47%). These data indicate that somatostatin decreases in AD and its expression may be linked with Abeta deposition.

Fate of marginal neuroblasts in the vomeronasal epithelium of adult mice.

Chemical stimuli are sensed through the olfactory and vomeronasal epithelia, and the sensory cells of both systems undergo neuronal turnover during adulthood. In the vomeronasal epithelium, stem cells adjacent to the basal lamina divide and migrate to replace two classes of sensory neurons: apical neurons that express G(i2alpha)-linked V1R vomeronasal receptors and project to the anterior accessory olfactory bulb, and basal neurons that express G(oalpha)-linked V2R receptors and project to the posterior accessory olfactory bulb. Most of the dividing cells are present in the margins of the epithelium and only migrate locally. Previous studies have suggested that these marginal cells may participate in growth, sensory cell replacement or become apoptotic before maturation; however, the exact fate of these cells have remained unclear. In this work we investigated the fate of these marginal cells by analyzing markers of neurogenesis (bromodeoxyuridine incorporation), apoptosis (caspase-3), and neuronal maturation (olfactory marker protein and Neurotrace Nissl stain). Our data reveal a pool of dividing cells in the epithelial margins that predominantly give rise to mature neurons and only rarely undergo apoptosis. Newly generated cells are several times more numerous than apoptotic cells. These marginal neuroblasts could therefore constitute a net neural addition zone during adulthood.