Search results for " bodies"
showing 10 items of 250 documents
Early steps in building the insect brain: neuroblast formation and segmental patterning in the developing brain of different insect species
2003
In insects, morphological, molecular and genetic studies have provided a detailed insight into the ontogenetic processes that shape the ventral nerve cord. On the other hand, owing to its complexity and less obvious segmental composition, the knowledge about the development of the brain is still fragmentary. A promising approach towards gaining insight into fundamental processes underlying brain development is the comparison of embryonic brain development among different insect species. However, so far such comparative analyses are scarce. In this review, we summarize and compare data on the early steps in brain formation in different hemi- and holometabolous insects. We show that basic asp…
Practical application of electron microscopy to neuromuscular diseases.
2013
Concerning individual neuromuscular conditions, electron microscopy may be considered “essential,” “helpful,” or “wasteful.” “Essential” electron microscopy should provide a clear diagnosis, because of the disease specificity of the ultrastructural findings, in particular as to inclusions within muscle fibers, such as cylindrical spirals and reducing bodies. Electron microscopy may be “helpful” in detecting ultrastructural features preceding typical light microscopic findings, for instance, undulating tubules in endothelial cells. Congenital, metabolic, and inflammatory myopathies may often be more easily and more reliably diagnosed by means of the electron microscope. Diagnostically “waste…
Role of AMPA receptor desensitization in short term depression : lessons from retinogeniculate synapses
2021
Repetitive synapse activity induces various forms of short-term plasticity. The role of presynaptic mechanisms such as residual Ca2+ and vesicle depletion in short-term facilitation and short-term depression is well established. On the other hand, the contribution of postsynaptic mechanisms such as receptor desensitization and saturation to short-term plasticity is less well known and often ignored. In this review, I will describe short-term plasticity in retinogeniculate synapses of relay neurons of the dorsal lateral geniculate nucleus (dLGN) to exemplify the synaptic properties that facilitate the contribution of AMPA receptor desensitization to short-term plasticity. These include high …
Origin of Drosophila mushroom body neuroblasts and generation of divergent embryonic lineages.
2012
Key to understanding the mechanisms that underlie the specification of divergent cell types in the brain is knowledge about the neurectodermal origin and lineages of their stem cells. Here, we focus on the origin and embryonic development of the four neuroblasts (NBs) per hemisphere in Drosophila that give rise to the mushroom bodies (MBs), which are central brain structures essential for olfactory learning and memory. We show that these MBNBs originate from a single field of proneural gene expression within a specific mitotic domain of procephalic neuroectoderm, and that Notch signaling is not needed for their formation. Subsequently, each MBNB occupies a distinct position in the developin…
Normal Function of the mushroom body defect Gene of Drosophila Is Required for the Regulation of the Number and Proliferation of Neuroblasts
1994
In the developing central nervous system of Drosophila, proliferation follows a reproducible and well-described spatial and temporal pattern. This pattern involves a defined number and distribution of neural stem cells (neuroblasts), as well as a precisely regulated time course of division of these neuroblasts. We show that mutations in the mushroom body defect (mud) gene interfere with the regulation of this pattern in a rather specific manner. In the abdominal neuromeres a subset of neuroblasts prolongs the period of proliferation. Additional daughter cells persist into the imago. Similar defects are expressed in the anterior ventral nerve cord and in the lateral central brain region. In …
Medium-chain triglycerides may improve memory in non-demented older adults: a systematic review of randomized controlled trials
2022
Abstract Background Ketosis has been exploited for its neuroprotective impact and treatment of neurological conditions via ketone production. Exogenous medium-chain triglyceride (MCT) supplementation may induce nutritional ketosis. The aim of this systematic review is to explore the effects of MCTs on memory function in older adults without cognitive impairment. Methods A systematic literature search of PubMed, Cochrane Library, Scopus, and Web of Science was employed from inception until April 2022 for randomized controlled trials (RCTs) in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, investigating the impact of MCT oils on com…
Assembly of fluorescent chimeric virus-like particles of canine parvovirus in insect cells
2004
Canine parvovirus (CPV) is a small non-enveloped ssDNA virus composed of the viral proteins VP1, VP2, and VP3 with a T=1 icosahedral symmetry. VP2 is nested in VP1 and the two proteins are produced by differential splicing of a primary transcript of the right ORF of the viral genome. The VP2 protein can be further proteolytically cleaved to form VP3. Previous studies have shown that VP1 and VP3 are unnecessary for capsid formation and consequently, that VP2 alone is sufficient for assembly. We have hypothesized that insertion of the enhanced green fluorescent protein (EGFP) at the N-terminus of VP2 could be carried out without altering assembly. To investigate the possibility to develop flu…
Late-Onset Globoid Cell Leukodystrophy: Unusual Ultrastructural Pathology and Subtotal β-Galactocerebrosidase Deficiency
1990
An 11-year-old girl was found to have severely reduced β-galactocerebrosidase activity as evidence of late-onset globoid cell leukodystrophy, while her mother had almost normal enzyme activity in circulating white blood cells. Clinically, the patient showed a remitting course marked by seizures, ataxia, white-matter disease on computed tomographic scan, and reduced conduction velocities of peripheral nerves. Symptoms improved somewhat around the age of 10 years. Two sural nerve biopsies, performed 6 years apart, disclosed a demyelinating neuropathy. By electron microscopy, membrane-bound vacuolar lysosomes in Schwann cells of myelinated axons, unlike the typical needlelike inclusions seen …
Intraepidermal morphologic manifestations in lysosomal diseases.
1989
This paper reports the ultrastructural findings for the epidermis of biopsied skin specimens in numerous lysosomal diseases, which can be grouped as follows: a) presence of vacuolar lysosomal residual bodies in mucopolysaccharidoses I, II and III, Salla disease, GM 2 -gangliosidoses and infantile type II glycogenosis; b) avacuolar lysosomal residual bodies in Niemann-Pick disease type C, mucolipidosis IV, Farber disease, Fabry disease, and late infantile and juvenile neuronal ceroid-lipofuscinoses; c) absence of lysosomal residual bodies in GM 2 -gangliosidoses, metachromatic leukodystrophy, Gaucher disease and sialidosis type III Whenever possible, a biopsy of the skin for morphological di…
Nuclear actin aggregation is a hallmark of anti-synthetase syndrome-induced dysimmune myopathy
2015
Objective: To analyze antisynthetase syndrome–associated myositis by modern myopathologic methods and to define its place in the spectrum of idiopathic inflammatory myopathies (IIMs). Methods: Skeletal muscle biopsies from antisynthetase syndrome–associated myositis and other IIMs from different institutions worldwide were analyzed by histopathology, quantitative PCR, and electron microscopy. Results: Myonuclear actin filament inclusions were identified as a unique morphologic hallmark of antisynthetase syndrome–associated myositis. Nuclear actin inclusions were never found in dermatomyositis, polymyositis, sporadic inclusion body myositis, autoimmune necrotizing myopathy associated with si…