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- Åberg, N David, 1970, et al.
(författare)
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Growth hormone increases connexin-43 expression in the cerebral cortex and hypothalamus.
- 2000
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Ingår i: Endocrinology. - 0013-7227. ; 141:10, s. 3879-86
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Tidskriftsartikel (refereegranskat)abstract
- Several studies indicate that systemic GH influences various brain functions. Connexin-43 forms gap junctions that mediate intercellular communication and establish the astroglial syncytium. We investigated the effects of peripheral administration of bovine GH (bGH) and recombinant human insulin-like growth factor I (rhIGF-I) on the expression of connexin-43 in the rat brain. Hypophysectomized female Sprague Dawley rats were substituted with cortisol (400 microg/kg x day) and L-T4 (10 microg/kg x day) and treated with either bGH (1 mg/kg x day) or rhIGF-I (0.85 mg/kg x day) for 19 days. The abundance of connexin-43 messenger RNA (mRNA) and protein in the brainstem, cerebral cortex, hippocampus, and hypothalamus was quantified by means of ribonuclease protection assays and Western blots. Treatment with bGH increased the amounts of connexin-43 mRNA and protein in the cerebral cortex and hypothalamus. No changes were found in the brainstem or hippocampus. Infusion of rhIGF-I did not affect connexin-43 mRNA or protein levels in any of the brain regions studied. These results show that administration of bGH increases the abundance of cx43 in specific brain regions, suggesting that GH may influence gap junction formation and thereby intercellular communication in the brain.
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| 5. |
- Bergqvist, Lena, 1958, et al.
(författare)
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Evidence of Construct Validity for the Modified Mental Fatigue Scale When Used in Persons with Cerebral Palsy
- 2020
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Ingår i: Developmental Neurorehabilitation. - : Informa UK Limited. - 1751-8423 .- 1751-8431. ; 23:4
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: Fatigue impacts negatively on everyday activities in individuals with cerebral palsy (CP). More knowledge is needed about how mental fatigue is manifested in this target group. The purpose of this study was to gather evidence about the validity of the modified Mental Fatigue Scale (m-MFS) in adults with CP. Methods: Mixed sequential exploratory design. The respondents were ten persons aged 22-56 with CP (MACS I-II). Results: The respondents perceived the m-MFS as easy to read and understand. Its structure was characterised as straightforward and the text of the rating options was deemed to assist identification with life situations. Very good agreement was seen between the respondents' and the instrument designers' intended meaning for the items in the m-MFS; the weighted kappa was 0.92. Conclusion: This study showed evidence of construct validity, based on response processes and content, for use of the modified MFS in adults with CP.
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| 8. |
- Björklund, Ulrika, 1970, et al.
(författare)
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Primary cultures from cerebral cortex and hippocampus enriched in glutamatergic and GABAergic neurons.
- 2010
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Ingår i: Neurochemical research. - : Springer Science and Business Media LLC. - 1573-6903 .- 0364-3190. ; 35:11, s. 1733-42
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Tidskriftsartikel (refereegranskat)abstract
- The aim was to define a primary culture system enriched in neurons using a defined culture medium, and characterize the model system as to cellular morphology and neuronal phenotypes. We found that these primary neuron enriched cultures from either newborn rat cerebral cortex or hippocampus contain small GABAergic and large glutamatergic neurons as well as astrocytes and microglia. Astrocytes in these cultures are morphologically differentiated with long, slender processes and interact with soluble factors responsible for induction and expression of the glutamate transporter GLT-1. The cultures achieve the highest expression of the vesicular glutamate transporter 1 (VGLUT1) and GLT-1 after 20 days in vitro. Conditioned media from these neuron enriched cultures also induced GLT-1 expression in primary astrocytic cultures, which were free from neurons. The amount of glutamatergic neurons guides the morphological maturation of astrocytes and GLT-1 expression both in the neuron enriched cultures and in the conditioned media supplemented astrocytic cultures. Interestingly, these cultures were not influenced or activated by the inflammatory stimulus lipopolysaccharide. This suggests that soluble factors from neurons protect microglia and astrocytes to become inflammatory reactive. In conclusion we have developed a well characterized culture model system enriched in neurons, taken from newborn rats and cultured in defined media. The neurons express different neuronal phenotypes. Such a model system is valuable when studying interactions between neurons and glial cells.
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| 9. |
- Blomstrand, Fredrik, 1969, et al.
(författare)
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Extent of intercellular calcium wave propagation is related to gap junction permeability and level of connexin-43 expression in astrocytes in primary cultures from four brain regions.
- 1999
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Ingår i: Neuroscience. - 0306-4522. ; 92:1, s. 255-65
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Tidskriftsartikel (refereegranskat)abstract
- Astrocytes are coupled via gap junctions, predominantly formed by connexin-43 proteins, into cellular networks. This coupling is important for the propagation of intercellular calcium waves and for the spatial buffering of K+. Using the scrape-loading/dye transfer technique, we studied gap junction permeability in rat astrocytes cultured from four different brain regions. The cultures were shown to display regional heterogeneity with the following ranking of the gap junction coupling strengths: hippocampus = hypothalamus > cerebral cortex = brain stem. Similar relative patterns were found in connexin-43 messenger RNA and protein levels using solution hybridization/RNase protection assay and western blots, respectively. The percentages of the propagation area of mechanically induced intercellular calcium waves for cortical, brain stem and hypothalamic astrocytes compared with hippocampal astrocytes were approximately 77, 42, and 52, respectively. Thus, the extent of calcium wave propagation was due to more than just gap junctional permeability as highly coupled hypothalamic astrocytes displayed relatively small calcium wave propagation areas. Incubation with 5-hydroxytryptamine decreased and incubation with glutamate increased the calcium wave propagation area in hippocampal (67% and 170% of the control, respectively) and in cortical astrocytes (82% and 163% of the control, respectively). Contrary to hippocampal and cortical astrocytes, the calcium wave propagation in brain stem astrocytes was increased by 5-hydroxytryptamine incubation (158% of control), while in hypothalamic astrocytes, no significant effects were seen. Similar effects from 5-hydroxytryptamine or glutamate treatments were observed on dye transfer, indicating an effect on the junctional coupling strength. These results demonstrate a strong relationship between connexin-43 messenger RNA levels, protein expression, and gap junction permeability among astroglial cells. Furthermore, our results suggest heterogeneity among astroglial cells from different brain regions in intercellular calcium signaling and in its differential modulation by neurotransmitters, probably reflecting functional requirements in various brain regions.
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