The cerebrovascular system provides crucial functions that maintain metabolic and homeostatic states of the brain. Despite its integral role of supporting cerebral viability, the topological ...organization of these networks remains largely uncharacterized. This void in our knowledge surmises entirely from current technological limitations that prevent the capturing of data through the entire depth of the brain. We report high-resolution reconstruction and analysis of the complete vascular network of the entire brain at the capillary level in adult female and male mice using a vascular corrosion cast procedure. Vascular network analysis of the whole brain revealed sex-related differences of vessel hierarchy. In addition, region-specific network analysis demonstrated different patterns of angioarchitecture between brain subregions and sex. Furthermore, our group is the first to provide a three-dimensional analysis of the angioarchitecture and network organization in a single reconstructed tomographic data set that encompasses all hierarchy of vessels in the brain of the adult mouse.
Display omitted
Astrocytes serve to maintain proper neuronal function and support neuronal viability, but remain largely understudied in research of cerebral ischemia. Astrocytic mitochondria are core participants ...in the metabolic activity of astrocytes. The objective of this study is to assess astrocyte mitochondrial competence during hypoxia and post-hypoxia reoxygenation and to determine cellular adaptive and pathological changes in the mitochondrial network. We hypothesize that during metabolic distress in astrocytes; mitochondrial networks undergo a shift in fission-fusion dynamics that results in a change in the morphometric state of the entire mitochondrial network. This mitochondrial network shift may be protective during metabolic distress by priming mitochondrial size and facilitating mitophagy. We demonstrated that hypoxia and post-hypoxia reoxygenation of rat primary astrocytes results in a redistribution of mitochondria to smaller sizes evoked by increased mitochondrial fission. Excessive mitochondrial fission corresponded to Drp-1 dephosphorylation at Ser 637, which preceded mitophagy of relatively small mitochondria. Reoxygenation of astrocytes marked the initiation of elevated mitophagic activity primarily reserved to the perinuclear region where a large number of the smallest mitochondria occurred. Although, during hypoxia astrocytic ATP content was severely reduced, after reoxygenation ATP content returned to near normoxic values and these changes mirrored mitochondrial superoxide production. Concomitant with these changes in astrocytic mitochondria, the number of astrocytic extensions declined only after 10-hours post-hypoxic reoxygenation. Overall, we posit a drastic mitochondrial network change that is triggered by a metabolic crisis during hypoxia; these changes are followed by mitochondrial degradation and retraction of astrocytic extensions during reoxygenation.
•3xTg AD mice develop tortuous arterioles and both arteriolar and capillary aneurysms.•Both capillary and non-capillary vessels progressively decline with age in 3xTg AD mice.•Hippocampal ...subregion-dependent changes to microvessels with age in 3xTg AD mice.•Cortical subregion-dependent changes to the microvasculature with age in 3xTg AD mice.
Heart disease and vascular disease positively correlate with the incidence of Alzheimer's disease (AD). Although there is ostensible involvement of dysfunctional cerebrovasculature in AD pathophysiology, the characterization of the specific changes and development of vascular injury during AD remains unclear. In the present study, we established a time-course for the structural changes and degeneration of the angioarchitecture in AD. We used cerebrovascular corrosion cast and µCT imaging to evaluate the geometry, topology, and complexity of the angioarchitecture in the brain of wild type and 3xTg AD mice. We hypothesized that changes to the microvasculature occur early during the disease, and these early identifiable aberrations would be more prominent in the brain subregions implicated in the cognitive decline of AD. Whole-brain analysis of the angioarchitecture indicated early morphological abnormalities and degeneration of microvascular networks in 3xTg AD mice. Our analysis of the hippocampus and cortical subregions revealed microvascular degeneration with onset and progression that was subregion dependent.
We assessed the importance of temperature, salinity, and prédation for the size structure of Zooplankton and provided insight into the future ecological structure and function of shallow lakes in a ...warmer climate. Artificial plants were introduced in eight comparable coastal shallow brackish lakes located at two contrasting temperatures: cold-temperate and Mediterranean climate region. Zooplankton, fish, and macroinvertebrates were sampled within the plants and at open-water habitats. The fish communities of these brackish lakes were characterized by small-sized individuals, highly associated with submerged plants. Overall, higher densities of small planktivorous fish were recorded in the Mediterranean compared to the cold-temperate region, likely reflecting temperature-related differences as have been observed in freshwater lakes. Our results suggest that fish prédation is the major control of Zooplankton size structure in brackish lakes, since fish density was related to a decrease in mean body size and density of Zooplankton and this was reflected in a unimodal shaped biomass-size spectrum with dominance of small sizes and low size diversity. Salinity might play a more indirect role by shaping Zooplankton communities toward more salt-tolerant species. In a global-warming perspective, these results suggest that changes in the trophic structure of shallow lakes in temperate regions might be expected as a result of the warmer temperatures and the potentially associated increases in salinity. The decrease in the density of largebodied Zooplankton might reduce the grazing on phytoplankton and thus the chances of maintaining the clear water state in these ecosystems.
Cerebrovascular pathology is pervasive in Alzheimer's disease (AD), yet it is unknown whether cerebrovascular dysfunction contributes to the progression or etiology of AD. In human subjects and in ...animal models of AD, cerebral hypoperfusion and hypometabolism are reported to manifest during the early stages of the disease and persist for its duration. Amyloid-β is known to cause cellular injury in both neurons and endothelial cells by inducing the production of reactive oxygen species and disrupting intracellular Ca2+ homeostasis. We present a mechanism for mitochondrial degeneration caused by the production of mitochondrial superoxide, which is driven by increased mitochondrial Ca2+ uptake. We found that persistent superoxide production injures mitochondria and disrupts electron transport in cerebrovascular endothelial cells. These observations provide a mechanism for the mitochondrial deficits that contribute to cerebrovascular dysfunction in patients with AD.
Optically stimulated luminescence in enaminones Lara-Camilo, A.; Villafañe-Bautista, Y.O.; de León-Alfaro, M.A. ...
Radiation physics and chemistry (Oxford, England : 1993),
February 2020, 2020-02-00, 20200201, Letnik:
167
Journal Article
Recenzirano
This work presents the first experimental results of optically stimulated luminescence in organic crystals type enaminones. Samples were synthesized by means of the condensation reaction of ...acetylacetone with four aromatics amines in acid medium. Component reactions were dissolved and heated in refluxing toluene under magnetic stirring during 14 h. Optically stimulated luminescence has been used in order to explore luminescent emission on organic solids. Optically stimulated luminescence characteristics were obtained using an automatic Lexsygsmart TL/OSL Luminescence reader. Organic crystals type enaminones exhibit good sensitivity to beta radiation. Organic crystals showed OSL response in exponential decay form. The OSL signal was increased as radiation dose was increased. Optically stimulated luminescence in organic crystals type enaminones has been reported at the first time.
•Organic crystals type enaminones were synthesized.•Luminescent crystalline crystals were analyzed.•OSL sensitivity in enaminones beta irradiated has been reported.•OSL response of organic crystals is presented.
Acceptance and effect on growth of two artificial wet diets for common octopus sub-adults were studied. These artificial wet diets were compounded of frozen shrimp or squid, both agglutinated with ...commercial gelatin. The diet based on frozen squid (SQ) promoted higher growth and conversion efficiency than the diet based on frozen shrimp (SH); while these rearing parameters of the SQ diet were not significantly lower than the ones obtained with the control diet (frozen squid). Feeding results indicate that gelatin did not reduce the palatability of the SQ diet, compared to the control diet. In conclusion, the good results obtained with the SQ diet support the hypothesis that this kind of wet artificial diet (a natural diet plus an agglutinant) can possibly be a base paste for other prepared diets.
PDF
