| 1. |
- Backman, Lars, et al.
(författare)
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Dopamine and training-related working-memory improvement
- 2013
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Ingår i: Neuroscience and Biobehavioral Reviews. - : Elsevier. - 0149-7634 .- 1873-7528. ; 37:9, s. 2209-2219
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Forskningsöversikt (refereegranskat)abstract
- Converging evidence indicates that the neurotransmitter dopamine (DA) is implicated in working-memory (WM) functioning and that WM is trainable. We review recent work suggesting that DA is critically involved in the ability to benefit from WM interventions. Functional MRI studies reveal increased striatal BOLD activity following certain forms of WM interventions, such as updating training. Increased striatal BOLD activity has also been linked to transfer of learning to non-trained WM tasks, suggesting a neural signature of transfer. The striatal BOLD signal is partly determined by DA activity. Consistent with this assertion, PET research demonstrates increased striatal DA release during updating of information in WM after training. Genetic studies indicate larger increases in WM performance post training for those who carry advantageous alleles of DA-relevant genes. These patterns of results corroborate the role of DA in WM improvement. Future research avenues include: (a) neuromodulatory correlates of transfer; (b) the potential of WM training to enhance DA release in older adults; (c) comparisons among different WM processes (i.e., updating, switching, inhibition) regarding regional patterns of training-related DA release; and (d) gene-gene interactions in relation to training-related WM gains.
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| 2. |
- Ferencz, Beata, et al.
(författare)
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The influence of APOE and TOMM40 polymorphisms on hippocampal volume and episodic memory in old age
- 2013
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Ingår i: Frontiers in Human Neuroscience. - : Frontiers Media SA. - 1662-5161. ; 7
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Tidskriftsartikel (refereegranskat)abstract
- Mitochondrial dysfunction is implicated in neurodegenerative disorders, such as Alzheimer's disease (AD). Translocase of outer mitochondrial membrane 40 (TOMM40) may be influential in this regard by influencing mitochondrial neurotoxicity. Little is known about the influence of the TOMM40 gene on hippocampal (HC) volume and episodic memory (EM), particularly in healthy older adults. Thus, we sought to discern the influence of TOMM40 single nucleotide polymorphisms (SNPs), which have previously been associated with medial temporal lobe integrity (rs11556505 and rs2075650), on HC volume and EM. The study sample consisted of individuals from the Swedish National Study on Aging and Care in Kungsholmen (SNAC-K) who were free of dementia and known neurological disorders, and 6087 years of age (n = 424). EM was measured by using a 16-item word list with a 2-min free recall period and delineation of the HC was performed manually. The influence of Apolipoprotein E (APOE) and TOMM40 was assessed by 2 x 2 ANOVAs and partial correlations. There was no effect of APOE and TOMM40 on EM performance and HC volume. However, partial correlations revealed that HC volume was positively associated with free recall performance (r = 0.21, p < 0.01, r(2) = 0.04). When further stratified for TOMM40, the observed association between HC volume and free recall in APOE epsilon 4 carriers was present in combination with TOMM40 rs11556505 any T (r = 0.28, p < 0.01, R-2 = 0.08) and rs2075650 any G (r = 0.28, p < 0.01, R-2 = 0.08) risk alleles. This pattern might reflect higher reliance on HC volume for adequate EM performance among APOE epsilon 4 carriers with additional TOMM40 risk alleles suggesting that the TOMM40 gene cannot merely be considered a marker of APOE genotype. Nevertheless, neither APOE nor TOMM40 influenced HC volume or EM in this population-based sample of cognitively intact individuals over the age of 60.
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| 3. |
- Soveri, Anna, et al.
(författare)
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Modulation of Auditory Attention by Training Evidence From Dichotic Listening
- 2013
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Ingår i: Experimental psychology (Göttingen). - : Hogrefe Publishing Group. - 1618-3169 .- 2190-5142. ; 60:1, s. 44-52
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Tidskriftsartikel (refereegranskat)abstract
- We studied the effects of training on auditory attention in healthy adults with a speech perception task involving dichotically presented syllables. Training involved bottom-up manipulation (facilitating responses from the harder-to-report left ear through a decrease of right-ear stimulus intensity), top-down manipulation (focusing attention on the left-ear stimuli through instruction), or their combination. The results showed significant training-related effects for top-down training. These effects were evident as higher overall accuracy rates in the forced-left dichotic listening (DL) condition that sets demands on attentional control, as well as a response shift toward left-sided reports in the standard DL task. Moreover, a transfer effect was observed in an untrained auditory-spatial attention task involving bilateral stimulation where top-down training led to a relatively stronger focus on left-sided stimuli. Our results indicate that training of attentional control can modulate the allocation of attention in the auditory space in adults. Malleability of auditory attention in healthy adults raises the issue of potential training gains in individuals with attentional deficits.
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| 4. |
- Abul-Kasim, Kasim, et al.
(författare)
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Advanced radiological work-up as an adjunct to decision in early reconstructive surgery in brachial plexus injuries
- 2010
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Ingår i: Journal of Brachial Plexus and Peripheral Nerve Injury. - : BioMed Central. - 1749-7221. ; 5, s. 14-
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundAs neurophysiologic tests may not reveal the extent of brachial plexus injury at the early stage, the role of early radiological work-up has become increasingly important. The aim of the study was to evaluate the concordance between the radiological and clinical findings with the intraoperative findings in adult patients with brachial plexus injuries.MethodsSeven consecutive male patients (median age 33; range 15-61) with brachial plexus injuries, caused by motor cycle accidents in 5/7 patients, who underwent extensive radiological work-up with magnetic resonance imaging (MRI), computed tomography myelography (CT-M) or both were included in this retrospective study. A total of 34 spinal nerve roots were evaluated by neuroradiologists at two different occasions. The degree of agreement between the radiological findings of every individual nerve root and the intraoperative findings was estimated by calculation of kappa coefficient (К-value). Using the operative findings as a gold standard, the accuracy, sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of the clinical findings and the radiological findings were estimated.ResultsThe diagnostic accuracy of radiological findings was 88% compared with 65% for the clinical findings. The concordance between the radiological findings and the intraoperative findings was substantial (К = 0.76) compared with only fair (К = 0.34) for the clinical findings. There were two false positive and two false negative radiological findings (sensitivity and PPV of 0.90; specificity and NPV of 0.87).ConclusionsThe advanced optimized radiological work-up used showed high reliability and substantial agreement with the intraoperative findings in adult patients with brachial plexus injury.
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| 5. |
- Addario, Barbara, 1974-
(författare)
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Alpha-actinin - an amazing journey through time and species
- 2011
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In eukaryotes, the actin cytoskeleton plays an important role in a large variety of cellular events. Its reorganization is regulated by a plethora of actin-modulating proteins, such as α-actinin. α-actinin is a ubiquitous actin-binding protein that belongs to the spectrin superfamily. This family, besides α-actinin, includes spectrin, dystrophin and utrophin. Phylogenetic analyses have indicated that the family members arose after several intragene duplications and rearrangements of a common ancestral α-actinin isoform. Up to the invertebrate-vertebrate bifurcation, organisms seemed to have a single, calcium-dependent α‑actinin. After the split, invertebrates have kept this single isoform, in contrast to vertebrates that acquired four distinct isoforms. Of the four vertebrate α-actinin isoforms, the two present in non-muscle cells are typically calcium sensitive while the two muscle isoforms are calcium insensitive. α-actinin in higher organisms is characterized by the presence of three distinct structural domains: a highly conserved N-terminal actin-binding domain, a central rod domain with four spectrin repeats and a calcium-binding C terminus with EF-hand motifs. In some primitive organisms, such as protozoa and fungi, the rod domain of α-actinin contains only one or two spectrin repeats. With the completion of an ever increasing number of genomes, new and atypical α‑actinin sequences had been available that have not been characterized yet. To obtain a firmer understanding of the evolutionary history of α-actinin, the main objective of this study was to identify, purify and biochemically characterize atypical α‑actinin or α‑actinin-like proteins of the parasite Entamoeba histolytica and of the fungus Schizosaccharomyces pombe. Our results show that both isoforms, despite the much shorter rod domain, are able to bind and cross-link actin filaments and therefore can be considered genuine α-actinins.
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| 6. |
- Addario, Barbara, et al.
(författare)
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Crystallization and preliminary X-ray analysis of the Entamoeba histolytica α-actinin-2 rod domain
- 2011
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Ingår i: Acta Crystallographica. Section F. - : International Union of Crystallography. - 1744-3091 .- 1744-3091. ; 67:10, s. 1214-1217
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Tidskriftsartikel (refereegranskat)abstract
- -Actinins form antiparallel homodimers that are able to cross-link actin filaments. The protein contains three domains: an N-terminal actin-binding domain followed by a central rod domain and a calmodulin-like EF-hand domain at the C-terminus. Here, crystallization of the rod domain of Entamoeba histolytica -actinin-2 is reported; it crystallized in space group P212121, with unit-cell parameters a = 47.8, b = 79.1, c = 141.8 Å. A Matthews coefficient VM of 2.6 Å3 Da-1 suggests that there are two molecules and 52.5% solvent content in the asymmetric unit. A complete native data set extending to a d-spacing of 2.8 Å was collected on beamline I911-2 at MAX-lab, Sweden.
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| 7. |
- Addario, Barbara, et al.
(författare)
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The domain structure of Entamoeba α-actinin2
- 2010
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Ingår i: Cellular & Molecular Biology Letters (Druk). - : Springer. - 1425-8153 .- 1689-1392. ; 15:4, s. 665-78
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Tidskriftsartikel (refereegranskat)abstract
- Entamoeba histolytica, a major agent of human amoebiasis, expresses two distinct forms of α-actinin, a ubiquitous actin-binding protein that is present in most eukaryotic organisms. In contrast to all metazoan α-actinins, in both isoforms the intervening rod domain that connects the N-terminal actin-binding domain with the C-terminal EF-hands is much shorter. It is suggested that these α-actinins may be involved in amoeboid motility and phagocytosis, so we cloned and characterised each domain of one of these α-actinins to better understand their functional role. The results clearly showed that the domains have properties very similar to those of conventional α-actinins.
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| 8. |
- Backman, Erik, 1972-, et al.
(författare)
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Encounters with nature, outdoor recreation and physical exercise
- 2012
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Konferensbidrag (refereegranskat)abstract
- During the past few decades, research into the social stratification in physical activity and sport has indicated that these practices are undisputedly correlated to possession of socioeconomic and cultural capital. Although sometimes claimed as socially equal, the practice of outdoor recreation appears to display the same pattern. However, recent studies of outdoor recreation-participants with low socioeconomic and cultural capital, indicate that the proportion also engaged in general physical activity is disproportionately high. Drawing on this finding, experiences of nature appears to be particularly important when striving for a life-long physically active lifestyle. The aim of this study is to further investigate the relation between the interest for outdoor recreation and the interest for physical activity.This study is part of a longitudinal Swedish study of habits regarding physical activity and sport during adolescence and adulthood. The individuals included in this study were first contacted in 1968 when they were 15 years old. The sample originally consisted of 2144 individuals, divided into 91 randomly selected school classes in Year 8 in four counties in Sweden. Since then, follow-up contact and information gathering have been conducted on six additional occasions, primarily via questionnaries sent by post. At the last collection, in 2007, a total of 1518 responses were recieved. By comparing groups in the mentioned empirical material, with various interests for outdoor recreation and/or physical activity, regarding variables such as: gender; social position; leisure habits; and previous experiences of sport and outdoor recreation; the relation between the interest for outdoor recreation and the interest for physical activity will be further explored.Through a multipel logistic regression analysis, preliminary results indicate that practice of physical activity and practice of outdoor recreation are related. Among outdoor recreation-participants with low socioeconomic and cultural capital, the proportion also engaged in physical activity appears to be disproportionally high. This finding motivates a further analysis of factors explaining the relation between the interest for physical activity and the interest for outdoor recreation. The results will be discussed in relation to the French sociologist Pierre Bourdieu’s concepts of habitus and taste.
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| 9. |
- Dahlin, Lars, et al.
(författare)
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Axillary nerve injury in young adults-An overlooked diagnosis? : early results of nerve reconstruction and nerve transfers
- 2012
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Ingår i: Journal of Plastic Surgery and Hand Surgery. - 2000-656X .- 2000-6764. ; 46:3-4, s. 257-261
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Tidskriftsartikel (refereegranskat)abstract
- An injury to the axillary nerve from a shoulder trauma can easily be overlooked. Spontaneous functional recovery may occur, but occasionally reconstructive surgery is required. The time frame for nerve reconstruction procedures is from a neurobiological view crucial for a good functional outcome. This study presents a group of operatively and non-operatively treated young adults with axillary nerve injuries caused by motorcycle accidents, where the diagnosis was set late. Ten young men (median age at trauma 13 years, range 9-24) with an axillary nerve injury were diagnosed by examination of shoulder function and electromyography (EMG). The patients had either a nerve reconstruction procedure or were treated conservatively and their recovery was monitored. The axillary nerve was explored and reconstructed at a median of 8 months (range 1-22 months) after trauma in 8/10 patients. Two patients were treated non-operatively. In 4/8 cases, a reconstruction with sural nerve graft was performed and in 1/8 case only exploration of the nerve was made (minor neuroma). In 3/8 cases a radial nerve branch transfer to the axillary nerve was chosen as the procedure. The shoulder was mobilised after 3 weeks with physiotherapy and the patients were monitored regularly. Functional recovery was observed in 9/10 cases (median follow up 11 months, range 7-64) with EMG signs of reinnervation in seven patients. Axillary nerve function should not be overlooked in young patients with a minor shoulder trauma. Nerve reconstruction can successfully recreate function.
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