18 research outputs found

    Social-economical situational concept

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    Modern geography considers the elements of space in their complicated interaction. All types of space are overlapped, forming zones with different degree of stability (social-economical situations - SES). SES with different scales always follow a society's life and under certain conditions are able to alter its spatial configuration. There exist two concepts to explain the processes of spatial-temporal localization of geosituations (Thisse,1996): the equilibrium concept and the external concept. Social-economical space is formed in the struggle of this contrary factors. The geosituational conception (SES), which we suggest, explains the spatial-temporal structure by means of the analysis of socio-ecologo-economical situations. The situations are movable formations. They are easy for alterations than stable geosystems. Thus the geosituational concept is the governing aspect of the environment modelling. The analysis of socio-ecologo-economical situations may be a primary weighty reason to make governing decision.

    Influence of repeated intravital extraction of eggs from sturgeon hybrids on their oogenesis under conditions of recirculation aquaculture system

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    Dynamics of cytomorphological characteristics of oocytes in ovaries is considered for two sturgeon hybrids: besters of the breed Burtlevskaya Huso huso (Linnaeus) x Acipenser ruthenus (Linnaeus) and the breed Aksayskaya Acipenser ruthenus x ( Huso huso x Acipenser ruthenus ) on the experimental data obtained under controlled conditions in the aquatic complex in Moscow (Russia) in 2010-2012. Methods of intravital eggs extraction, ultrasound diagnostics, biopsy with the probe, anesthesia and histological analysis are applied. Structure of membrane is similar for straight sturgeon species and hybrids, but the membrane thickness and the term of its emergence on certain maturity stage are somewhat different, so the eggs of bester could be distinguished by the oocyte membrane thickness. Mean interspawning interval for the hybrids in conditions of recirculation aquaculture system at water temperature 20-21 °C is determined as 10-12 months

    Interplay between n-3 and n-6 long-chain polyunsaturated fatty acids and the endocannabinoid system in brain protection and repair.

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    The brain is enriched in arachidonic acid (ARA) and docosahexaenoic acid (DHA), long-chain polyunsaturated fatty acids (LCPUFA) of the n-6 and n-3 series, respectively. Both are essential for optimal brain development and function. Dietary enrichment with DHA and other long-chain n-3 PUFA, such as eicosapentaenoic acid (EPA) have shown beneficial effects on learning and memory, neuroinflammatory processes and synaptic plasticity and neurogenesis. ARA, DHA and EPA are precursors to a diverse repertoire of bioactive lipid mediators, including endocannabinoids. The endocannabinoid system comprises cannabinoid receptors, their endogenous ligands, the endocannabinoids, and their biosynthetic and degradation enzymes. Anandamide (AEA) and 2-archidonoylglycerol (2-AG) are the most widely studied endocannabinoids, and are both derived from phospholipid-bound ARA. The endocannabinoid system also has well established roles in neuroinflammation, synaptic plasticity and neurogenesis, suggesting an overlap in the neuroprotective effects observed with these different classes of lipids. Indeed, growing evidence suggests a complex interplay between n-3 and n-6 LCPUFA and the endocannabinoid system. For example, long-term DHA and EPA supplementation reduces AEA and 2-AG levels, with reciprocal increases in levels of the analogous endocannabinoid-like DHA and EPA-derived molecules. This review summarises current evidence of this interplay and discusses the therapeutic potential for brain protection and repair

    Gi/o-protein coupled receptors in the aging brain

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    Cells translate extracellular signals to regulate processes such as differentiation, metabolism and proliferation, via transmembranar receptors. G protein-coupled receptors (GPCRs) belong to the largest family of transmembrane receptors, with over 800 members in the human species. Given the variety of key physiological functions regulated by GPCRs, these are main targets of existing drugs. During normal aging, alterations in the expression and activity of GPCRs have been observed. The central nervous system (CNS) is particularly affected by these alterations, which results in decreased brain functions, impaired neuroregeneration, and increased vulnerability to neuropathologies, such as Alzheimer's and Parkinson diseases. GPCRs signal via heterotrimeric G proteins, such as Go, the most abundant heterotrimeric G protein in CNS. We here review age-induced effects of GPCR signaling via the Gi/o subfamily at the CNS. During the aging process, a reduction in protein density is observed for almost half of the Gi/o-coupled GPCRs, particularly in age-vulnerable regions such as the frontal cortex, hippocampus, substantia nigra and striatum. Gi/o levels also tend to decrease with aging, particularly in regions such as the frontal cortex. Alterations in the expression and activity of GPCRs and coupled G proteins result from altered proteostasis, peroxidation of membranar lipids and age-associated neuronal degeneration and death, and have impact on aging hallmarks and age-related neuropathologies. Further, due to oligomerization of GPCRs at the membrane and their cooperative signaling, down-regulation of a specific Gi/o-coupled GPCR may affect signaling and drug targeting of other types/subtypes of GPCRs with which it dimerizes. Gi/o-coupled GPCRs receptorsomes are thus the focus of more effective therapeutic drugs aiming to prevent or revert the decline in brain functions and increased risk of neuropathologies at advanced ages.This work was supported by Fundação para a Ciência e Tecnologia, Centro 2020 and Portugal 2020, the COMPETE program, QREN, and the European Union (FEDER program) via the GoBack project (PTDC/CVT-CVT/32261/2017), the pAGE program (Centro-01-0145-FEDER-000003), and Institute for Biomedicine iBiMED (UID/BIM/04501/2013; UID/BIM/04501/2019).publishe

    Loss of CB1 receptors leads to decreased cathepsin D levels and accelerated lipofuscin accumulation in the hippocampus

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    Early onset of age-related changes in the brain of cannabinoid 1 receptor knockout (Cnr1−/−) mice suggests that cannabinoid 1 (CB1) receptor activity significantly influences the progression of brain aging. In the present study we show that lack of CB1 receptors leads to a significant increase in lipofuscin accumulation and a reduced expression and activity of cathepsin D, lysosomal protease implicated in the degradation of damaged macromolecules, in the hippocampus of 12-month-old mice. The impaired clearance of damaged macromolecules due to the low cathepsin D levels and not enhanced oxidative stress may be responsible for the lipofuscin accumulation because macromolecule oxidation levels were comparable between the genotypes within the same age group. The altered levels of autophagy markers p62 and LC3-II suggest that autophagy is upregulated in CB1 knockout mice. Increased autophagic

    Inhibition of striatonigral autophagy as a link between cannabinoid intoxication and impairment of motor coordination

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    The use of cannabis is rapidly expanding worldwide. Thus, innovative studies aimed to identify, understand and potentially reduce cannabis-evoked harms are warranted. Here, we found that D 9 -tetrahydrocannabinol, the psychoactive ingredient of cannabis, disrupts autophagy selectively in the striatum, a brain area that controls motor behavior, both in vitro and in vivo. Boosting autophagy, either pharmacologically (with temsirolimus) or by dietary intervention (with trehalose), rescued the D 9 -tetrahydrocannabinol-induced impairment of motor coordination in mice. The combination of conditional knockout mouse models and viral vector-mediated autophagymodulating strategies in vivo showed that cannabinoid CB1 receptors located on neurons belonging to the direct (striatonigral) pathway are required for the motor-impairing activity of D 9 - tetrahydrocannabinol by inhibiting local autophagy. Taken together, these findings identify inhibition of autophagy as an unprecedented mechanistic link between cannabinoids and motor performance, and suggest that activators of autophagy might be considered as potential therapeutic tools to treat specific cannabinoid-evoked behavioral alterations
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