Both cross-sectional and longitudinal studies in the United States have shown consistent changes between college age and middle adulthood. There appear to be declines in 3 of the 5 major factors of personality--Neuroticism, Extraversion, and Openness--and increases in Agreeableness and Conscientiousness. To examine cross-cultural generalizability of these findings, translations of the Revised NEO Personality Inventory were administered to samples in Germany, Italy, Portugal, Croatia, and South Korea (N = 7,363). Similar patterns of age differences were seen in each country, for both men and women. Common trends were also seen for the more specific traits that define the major factors. Because these nations differ substantially in culture and recent history, results suggest the hypothesis that these are universal maturational changes in adult personality.
Machado-Joseph disease is the most frequently found dominantly-inherited cerebellar ataxia. Over-repetition of a CAG trinucleotide in the MJD1 gene translates into a polyglutamine tract within the ataxin 3 protein, which upon proteolysis may trigger Machado-Joseph disease. We investigated the role of calpains in the generation of toxic ataxin 3 fragments and pathogenesis of Machado-Joseph disease. For this purpose, we inhibited calpain activity in mouse models of Machado-Joseph disease by overexpressing the endogenous calpain-inhibitor calpastatin. Calpain blockage reduced the size and number of mutant ataxin 3 inclusions, neuronal dysfunction and neurodegeneration. By reducing fragmentation of ataxin 3, calpastatin overexpression modified the subcellular localization of mutant ataxin 3 restraining the protein in the cytoplasm, reducing aggregation and nuclear toxicity and overcoming calpastatin depletion observed upon mutant ataxin 3 expression. Our findings are the first in vivo proof that mutant ataxin 3 proteolysis by calpains mediates its translocation to the nucleus, aggregation and toxicity and that inhibition of calpains may provide an effective therapy for Machado-Joseph disease.
The consumption of caffeine modulates working and reference memory through the antagonism of adenosine A 2A receptors (A 2A Rs) controlling synaptic plasticity processes in hippocampal excitatory synapses. Fear memory essentially involves plastic changes in amygdala circuits. However, it is unknown if A 2A Rs in the amygdala regulate synaptic plasticity and fear memory. We report that A 2A Rs in the amygdala are enriched in synapses and located to glutamatergic synapses, where they selectively control synaptic plasticity rather than synaptic transmission at a major afferent pathway to the amygdala. Notably, the downregulation of A 2A Rs selectively in the basolateral complex of the amygdala, using a lentivirus with a silencing shRNA (small hairpin RNA targeting A 2A R (shA 2A R)), impaired fear acquisition as well as Pavlovian fear retrieval. This is probably associated with the upregulation and gain of function of A 2A Rs in the amygdala after fear acquisition. The importance of A 2A Rs to control fear memory was further confirmed by the ability of SCH58261 (0.1 mg/kg; A 2A R antagonist), caffeine (5 mg/kg), but not DPCPX (0.5 mg/kg; A 1 R antagonist), treatment for 7 days before fear conditioning onwards, to attenuate the retrieval of context fear after 24-48 h and after 7-8 days. These results demonstrate that amygdala A 2A Rs control fear memory and the underlying process of synaptic plasticity in this brain region. This provides a neurophysiological basis for the association between A 2A R polymorphisms and phobia or panic attacks in humans and prompts a therapeutic interest in A 2A Rs to manage fear-related pathologies.
The aim of the study was to evaluate the possible relationships between stress tolerance, training load, banal infections and salivary parameters during 4 weeks of regular training in fifteen basketball players. The Daily Analysis of Life Demands for Athletes' questionnaire (sources and symptoms of stress) and the Wisconsin Upper Respiratory Symptom Survey were used on a weekly basis. Salivary cortisol and salivary immunoglobulin A (SIgA) were collected at the beginning (before) and after the study, and measured by enzyme‐linked immunosorbent assay (ELISA). Ratings of perceived exertion (training load) were also obtained. The results from ANOVA with repeated measures showed greater training loads, number of upper respiratory tract infection episodes and negative sensation to both symptoms and sources of stress, at week 2 (p < 0.05). Significant increases in cortisol levels and decreases in SIgA secretion rate were noted (before to after). Negative sensations to symptoms of stress at week 4 were inversely and significantly correlated with SIgA secretion rate. A positive and significant relationship between sources and symptoms of stress at week 4 and cortisol levels were verified. In summary, an approach incorporating in conjunction psychometric tools and salivary biomarkers could be an efficient means of monitoring reaction to stress in sport. Copyright © 2010 John Wiley & Sons, Ltd.
Our findings provide a demonstration that synaptotoxicity and gliosis are precocious events in MJD and that caffeine and A2A R inactivation decrease MJD-associated striatal pathology, which paves the way to consider A2A Rs as novel therapeutic targets to manage MJD.
Machado-Joseph Disease (MJD) is the most prevalent autosomal dominantly inherited cerebellar ataxia. It is caused by an expanded CAG repeat in the ATXN3 gene, which translates into a polyglutamine tract within the ataxin-3 protein. Present treatments are symptomatic and do not prevent disease progression. As calpain overactivation has been shown to contribute to mutant ataxin-3 proteolysis, translocation to the nucleus, inclusions formation and neurodegeneration, we investigated the potential role of calpain inhibition as a therapeutic strategy to alleviate MJD pathology. For this purpose, we administered orally the calpain inhibitor BDA-410 to a lentiviral mouse model of MJD. Western-blot and immunohistochemical analysis revealed the presence of N- and C-terminal mutant ataxin-3 fragments and the colocalization of large inclusions with cleaved caspase-3 in the mice brain. Oral administration of the calpain inhibitor BDA-410 decreased both fragments formation and full-length ataxin-3 levels, reduced aggregation of mutant ataxin-3 and prevented cell injury and striatal and cerebellar degeneration. Importantly, in correlation with the preserved cerebellar morphology, BDA-410 prevented motor behavioural deficits. In conclusion, BDA-410 alleviates Machado-Joseph neuropathology and may therefore be an effective therapeutic option for MJD.
This investigation examined the impact of a 17-d training period (that included basketball-specific training, sprints, intermittent running exercises, and weight training, prior to an international championship competition) on salivary immunoglobulin A (SIgA) levels in 10 subjects (athletes and staff members) from a national basketball team, as a biomarker for mucosal immune defence. Unstimulated saliva samples were collected at rest at the beginning of the preparation for the Pan American Games and 1 d before the first game. The recovery interval from the last bout of exercise was 4 h. The SIgA level was measured using enzyme-linked immunosorbent assay and expressed as absolute concentrations, secretion rate, and SIgA level relative to total protein. The decrease in SIgA levels following training was greater in athletes than in support staff; however, no significant differences between the two groups were detected. A decrease in SIgA level, regardless of the method used to express IgA results, was verified for athletes. Only one episode of upper respiratory tract illness symptoms was reported, and it was not associated with changes in SIgA levels. In summary, a situation of combined stress for an important championship was found to decrease the level of SIgA-mediated immune protection at the mucosal surface in team members, with greater changes observed in the athletes.
Machado-Joseph disease (MJD) is a fatal, dominantly inherited neurodegenerative disorder associated with an expanded polyglutamine tract within the ataxin-3 protein, and characterized by progressive impairment of motor coordination, associated with neurodegeneration of specific brain regions, including cerebellum and striatum. The currently available therapies do not allow modification of disease progression. Neuropeptide Y (NPY) has been shown to exert potent neuroprotective effects by multiple pathways associated with the MJD mechanisms of disease. Thus, we evaluated NPY levels in MJD and investigated whether raising NPY by gene transfer would alleviate neuropathological and behavioural deficits in cerebellar and striatal mouse models of the disease. For that, a cerebellar transgenic and a striatal lentiviral-based models of MJD were used. NPY overexpression in the affected brain regions in these two mouse models was obtained by stereotaxic injection of adeno-associated viral vectors encoding NPY. Up to 8 weeks after viral injection, balance and motor coordination behaviour and neuropathology were analysed. We observed that NPY levels were decreased in two MJD patients' cerebella and in striata and cerebella of disease mouse models. Furthermore, overexpression of NPY alleviated the motor coordination impairments and attenuated the related neuropathological parameters, preserving cerebellar volume and granular layer thickness, reducing striatal lesion and decreasing mutant ataxin-3 aggregation. Additionally, NPY mediated increase of brain-derived neurotrophic factor levels and decreased neuroinflammation markers. Our data suggest that NPY is a potential therapeutic strategy for MJD.
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