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- Johansson, Inger, 1962, et al.
(författare)
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Proliferative and protective effects of growth hormone secretagogues on adult rat hippocampal progenitor cells.
- 2008
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Ingår i: Endocrinology. - : The Endocrine Society. - 0013-7227 .- 1945-7170. ; 149:5, s. 2191-9
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Tidskriftsartikel (refereegranskat)abstract
- Progenitor cells in the subgranular zone of the hippocampus may be of significance for functional recovery after various injuries because they have a regenerative potential to form new neuronal cells. The hippocampus has been shown to express the GH secretagogue (GHS) receptor 1a, and recent studies suggest GHS to both promote neurogenesis and have neuroprotective effects. The aim of the present study was to investigate whether GHS could stimulate cellular proliferation and exert cell protective effects in adult rat hippocampal progenitor (AHP) cells. Both hexarelin and ghrelin stimulated increased incorporation of (3)H-thymidine, indicating an increased cell proliferation. Furthermore, hexarelin, but not ghrelin, showed protection against growth factor deprivation-induced apoptosis, as measured by annexin V binding and caspase-3 activity and also against necrosis, as measured by lactate dehydrogenase release. Hexarelin activated the MAPK and the phosphatidylinositol 3-kinase/Akt pathways, whereas ghrelin activated only the MAPK pathway. AHP cells did not express the GHS receptor 1a, but binding studies could show specific binding of both hexarelin and ghrelin, suggesting effects to be mediated by an alternative GHS receptor subtype. In conclusion, our results suggest a differential effect of hexarelin and ghrelin in AHP cells. We have demonstrated stimulation of (3)H-thymidine incorporation with both hexarelin and ghrelin. Hexarelin, but not ghrelin, also showed a significant inhibition of apoptosis and necrosis. These results suggest a novel cell protective and proliferative role for GHS in the central nervous system.
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| 2. |
- Åberg, Maria A I, 1972, et al.
(författare)
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Cardiovascular fitness is associated with cognition in young adulthood.
- 2009
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 1091-6490.
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Tidskriftsartikel (refereegranskat)abstract
- During early adulthood, a phase in which the central nervous system displays considerable plasticity and in which important cognitive traits are shaped, the effects of exercise on cognition remain poorly understood. We performed a cohort study of all Swedish men born in 1950 through 1976 who were enlisted for military service at age 18 (N = 1,221,727). Of these, 268,496 were full-sibling pairs, 3,147 twin pairs, and 1,432 monozygotic twin pairs. Physical fitness and intelligence performance data were collected during conscription examinations and linked with other national databases for information on school achievement, socioeconomic status, and sibship. Relationships between cardiovascular fitness and intelligence at age 18 were evaluated by linear models in the total cohort and in subgroups of full-sibling pairs and twin pairs. Cardiovascular fitness, as measured by ergometer cycling, positively associated with intelligence after adjusting for relevant confounders (regression coefficient b = 0.172; 95% CI, 0.168-0.176). Similar results were obtained within monozygotic twin pairs. In contrast, muscle strength was not associated with cognitive performance. Cross-twin cross-trait analyses showed that the associations were primarily explained by individual specific, non-shared environmental influences (>/=80%), whereas heritability explained <15% of covariation. Cardiovascular fitness changes between age 15 and 18 y predicted cognitive performance at 18 y. Cox proportional-hazards models showed that cardiovascular fitness at age 18 y predicted educational achievements later in life. These data substantiate that physical exercise could be an important instrument for public health initiatives to optimize educational achievements, cognitive performance, as well as disease prevention at the society level.
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| 3. |
- Åberg, Maria A I, 1972, et al.
(författare)
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Fish intake of Swedish male adolescents is a predictor of cognitive performance.
- 2009
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Ingår i: Acta paediatrica (Oslo, Norway : 1992). - : Wiley. - 1651-2227 .- 0803-5253. ; 98:3, s. 555-60
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Tidskriftsartikel (refereegranskat)abstract
- AIM: Fish intake is reported to positively influence cognitive performance in infants and the elderly. In a longitudinal cohort study, we evaluated how fish consumption related to later cognitive performance in healthy young male adolescents. METHODS: In 2000, all 15-year-olds (n = 18 158; 9260 males) in the western region of Sweden were requested to complete an extensive questionnaire with items on diseases, fish consumption and socioeconomic status. Questionnaire data from the male responders (n = 4792, response rate 52%) were linked with records on subsequent intelligence test performance at age 18 from the Swedish Military Conscription Register (n = 3972). Multivariate linear models were used to estimate associations between fish intake and cognitive performance, adjusting for potential confounders. RESULTS: There was a positive association between the number of times having fish meals per week at age 15 and cognitive performance measured 3 years later. Fish consumption of more than once per week compared to less than once per week was associated with higher stanine scores in combined intelligence (0.58 units; 95% confidence interval 0.39, 0.76), in verbal performance (0.45; 0.27, 0.63) and in visuospatial performance (0.50; 0.31, 0.69). The association between fish consumption and the 3 intelligence scores was the same in lowly and highly educated groups. This indicates that education did not influence the association between the frequency of fish meals consumed and cognitive performance. CONCLUSION: Frequent fish intake at age 15 was associated with significantly higher cognitive performance 3 years later.
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| 4. |
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| 5. |
- Åberg, N David, 1970, et al.
(författare)
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Peripheral administration of GH induces cell proliferation in the brain of adult hypophysectomized rats.
- 2009
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Ingår i: The Journal of endocrinology. - 1479-6805. ; 201:1, s. 141-50
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Tidskriftsartikel (refereegranskat)abstract
- IGF-I treatment has been shown to enhance cell genesis in the brains of adult GH- and IGF-I-deficient rodents; however, the influence of GH therapy remains poorly understood. The present study investigated the effects of peripheral recombinant bovine GH (bGH) on cellular proliferation and survival in the neurogenic regions (subventricular zone (SVZ), and dentate gyrus of the hippocampus), as well as the corpus callosum, striatum, parietal cortex, and piriform cortex. Hypopituitarism was induced in female rats by hypophysectomy, and the rats were supplemented with thyroxine and cortisone acetate. Subsequently, the rats received daily s.c. injections of bGH for either 6 or 28 days respectively. Following 5 days of peripheral bGH administration, the number of bromodeoxyuridine (BrdU)-positive cells was increased in the hippocampus, striatum, parietal cortex, and piriform cortex after 6 and 28 days. In the SVZ, however, BrdU-positive cells increased only after 28 days of bGH treatment. No significant change was observed in the corpus callosum. In the hippocampus, after 28 days of bGH treatment, the number of BrdU/NeuN-positive cells was increased proportionally to increase the number of BrdU-positive cells. (3)H-thymidine incorporation in vitro revealed that 24 h of bGH exposure was sufficient to increase cell proliferation in adult hippocampal progenitor cells. This study shows for the first time that 1) peripheral bGH treatment increased the number of newborn cells in the adult brain and 2) bGH exerted a direct proliferative effect on neuronal progenitor cells in vitro.
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| 6. |
- Åberg, N David, 1970, et al.
(författare)
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Peripheral infusion of insulin-like growth factor-I increases the number of newborn oligodendrocytes in the cerebral cortex of adult hypophysectomized rats.
- 2007
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Ingår i: Endocrinology. - : The Endocrine Society. - 0013-7227 .- 1945-7170. ; 148:8, s. 3765-72
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Tidskriftsartikel (refereegranskat)abstract
- We have previously shown that recombinant human (rh) IGF-I induces cell proliferation and neurogenesis in the hippocampus of hypophysectomized rats. In the current investigation, we determined the effects of rhIGF-I on proliferation and differentiation in the cerebral cortex. Adult hypophysectomized rats were injected with bromodeoxyuridine (BrdU) to label newborn cells (once a day for the first 5 d), and rhIGF-I was administered peripherally for 6 or 20 d. In the cerebral cortex, the number of BrdU-labeled cells increased after 20 d but not after 6 d of rhIGF-I infusion. This suggests that rhIGF-I enhances the survival of newborn cells in the cerebral cortex. Using BrdU labeling combined with the oligodendrocyte-specific markers myelin basic protein and 2',3'-cyclic nucleotide 3'-phosphodiesterase, we demonstrated an increase in oligodendrogenesis in the cerebral cortex. The total amount of myelin basic protein and 2',3'-cyclic nucleotide 3'-phosphodiesterase was also increased on Western blots of homogenates of the cerebral cortex, confirming the immunohistochemical findings. Also, we observed an increase in the number of capillary-associated BrdU-positive cells, although total capillary area was not increased. rhIGF-I treatment did not affect cortical astrogliogenesis and neurogenesis was not observed. The ability of rhIGF-I to induce cortical oligodendrogenesis may have implications for the regenerative potential of the cortex.
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