Search results for "nucleus"
showing 10 items of 1803 documents
Expression of MAP1a and MAP1b in the ganglionic eminence and the internal capsule of the human fetal brain.
2001
The expression of microtubule-associated proteins 1a and 1b (MAP1a and 1b) were investigated in two transient structures, the ganglionic eminence (GE) being a prominent part of the telencephalic proliferative zone and the perireticular nucleus (PR) within the internal capsule (IC). Anti-MAP1a immunolabels PR neurons from 18 weeks of gestation (wg) onwards, whereas anti-MAP1b immunolabels long IC fibers between 18 and 22 wg. MAP1b is further present in thalamic fibers that seem to terminate at the medial margin of the GE, in a moderate number of cells of the GE and its medial extension, the gangliothalamic body (GTB). From 26 to 33 wg MAP1b is expressed in short fiber bundles of the IC, a fe…
Association of basal forebrain volumes and cognition in normal aging.
2013
The basal forebrain cholinergic system (BFCS) is known to undergo moderate neurodegenerative alterations during normal aging and severe atrophy in Alzheimer's disease (AD). It has been suggested that functional and structural alterations of the BFCS mediate cognitive performance in normal aging and AD. But, it is still unclear to what extend age-associated cognitive decline can be related to BFCS in normal aging. We analyzed the relationship between BFCS volume and cognition using MRI and a comprehensive neuropsychological test battery in a cohort of 43 healthy elderly subjects spanning the age range from 60 to 85 years. Most notably, we found significant associations between general intell…
CRMP-4 expression in the adult cerebral cortex and other telencephalic areas of the lizard Podarcis hispanica.
2002
The control of neuritogenesis is crucial for the development, maturation and regeneration of the nervous system. The collapsin response-mediated protein 4 (CRMP-4) is a member of a family of proteins that are involved in neuronal differentiation and axonal outgrowth. In rodents, this protein is expressed in recently generated neurons such as some granule neurons of the dentate gyrus, as well as in certain differentiated neurons undergoing neurite outgrowth or synaptogenesis during adulthood. Since CRMP-4 protein appears to be highly conserved throughout the evolutionary scale, we have used immunocytochemistry to study its distribution in the lizard cerebral cortex. We have found pronounced …
Telomere shortening and chromosomal instability abrogates proliferation of adult but not embryonic neural stem cells.
2004
Chromosome integrity is essential for cell viability and, therefore, highly proliferative cell types require active telomere elongation mechanisms to grow indefinitely. Consistently, deletion of telomerase activity in a genetically modified mouse strain results in growth impairments in all highly proliferative cell populations analyzed so far. We show that telomere attrition dramatically impairs the in vitro proliferation of adult neural stem cells (NSCs) isolated from the subventricular zone (SVZ) of telomerase-deficient adult mice. Reduced proliferation of postnatal neurogenic progenitors was also observed in vivo, in the absence of exogenous mitogenic stimulation. Strikingly, severe telo…
Chromatin modifiers and recombination factors promote a telomere fold-back structure, that is lost during replicative senescence.
2020
Telomeres have the ability to adopt a lariat conformation and hence, engage in long and short distance intra-chromosome interactions. Budding yeast telomeres were proposed to fold back into subtelomeric regions, but a robust assay to quantitatively characterize this structure has been lacking. Therefore, it is not well understood how the interactions between telomeres and non-telomeric regions are established and regulated. We employ a telomere chromosome conformation capture (Telo-3C) approach to directly analyze telomere folding and its maintenance in S. cerevisiae. We identify the histone modifiers Sir2, Sin3 and Set2 as critical regulators for telomere folding, which suggests that a dis…
Transient features of the thalamic reticular nucleus in the human foetal brain
1998
The architectonic organization and neuronal types of the human foetal reticular nucleus (RN)--with special reference to transient characteristics--have been investigated using antisera against calretinin, parvalbumin and neurofilament epitopes of somata and dendrites (SMI 311). The RN consists of four subdivisions (clearly distinguishable in the 6/7th gestational month): The main portion appears as a prominent structure on account of its extension and high packing density of neurons which coexpress calretinin and parvalbumin. These two calcium-binding proteins are also expressed by the perireticular nucleus forming a conspicuous grey within the internal capsule. Perireticular cells form clu…
Brain Cortical Complexity and Subcortical Morphometrics in Lifelong Premature Ejaculation
2020
Premature ejaculation (PE) is the most common male sexual dysfunction. The brain disturbances that cause this disorder remain poorly understood. This study aimed to investigate how the morphology of cortical and subcortical brain structures differed in PE, how these morphologic differences were associated with severity measures of PE, such as intravaginal ejaculatory latency time (IELT), and how these cortical and subcortical structures were causally connected through mediation analysis. Anatomical MRI scans were acquired from 39 male participants, 23 with PE (28.78 ± 4.32 years), and 16 without PE (27.88 ± 3.65 years). We used a subcortical analysis package within FSL to perform subcortica…
The designer cytokine hyper-interleukin-6 is a potent activator of STAT3-dependent gene transcription in vivo and in vitro.
1999
Interleukin-6 (IL-6) triggers pivotal pathways in vivo. The designer protein hyper-IL-6 (H-IL-6) fuses the soluble IL-6 receptor (sIL-6R) through an intermediate linker with IL-6. The intracellular pathways that are triggered by H-IL-6 are not defined yet. Therefore, we studied the molecular mechanisms leading to H-IL-6-dependent gene activation. H-IL-6 stimulates haptoglobin mRNA expression in HepG2 cells, which is transcriptionally mediated as assessed by run-off experiments. The increase in haptoglobin gene transcription correlates with higher nuclear translocation of tyrosine-phosphorylated STAT3 and its DNA binding. As H-IL-6 stimulates STAT3-dependent gene transcription, we compared t…
Paclitaxel and beta-lapachone synergistically induce apoptosis in human retinoblastoma Y79 cells by downregulating the levels of phospho-Akt.
2009
Paclitaxel (PTX) and beta-lapachone (LPC) are naturally occurring compounds that have shown a large spectrum of anticancer activity. In this article we show for the first time that PTX/LPC combination induces potent synergistic apoptotic effects in human retinoblastoma Y79 cells. Combination of suboptimal doses of PTX (0.3 nM) and LPC (1.5 microM) caused biochemical and morphological signs of apoptosis at 48 h of treatment. These effects were accompanied by potent lowering in inhibitor of apoptosis proteins and by activation of Bid and caspases 3 and 6 with lamin B and PARP breakdown. PTX/LPC combination acted by favoring p53 stabilization through a lowering in p-Akt levels and in ps166-MDM…
Acrylamide catalytically inhibits topoisomerase II in V79 cells.
2010
The vinyl monomer acrylamide is characterized by the presence of an alpha,beta-unsaturated carbonyl group that makes it reactive towards thiol, hydroxyl or amino groups and towards the nucleophilic centers in DNA. The ability of acrylamide to chemically modify protein thiols has prompted us to consider topoisomerase II as one possible target of acrylamide, since agents targeting protein sulfhydryl groups act as either catalytic inhibitors or poisons of topoisomerase II. Nuclear extracts from V79 Chinese hamster cells incubated with acrylamide reduced topoisomerase II activity as inferred by an inability to convert kinetoplast DNA to the decatenated form. Nuclear extracts incubated with acry…