| 1. |
- Aaltonen, Olli, et al.
(författare)
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Brain responses reveal hardwired detection of native-language rule violations
- 2008
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Ingår i: Neuroscience Letters. - : Elsevier BV. - 0304-3940 .- 1872-7972. ; 444:1, s. 56-59
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Tidskriftsartikel (refereegranskat)abstract
- Mismatch negativity (MMN) is a neural correlate of the preattentive detection of any change in the acoustic characteristics of sounds. Here we provide evidence that violations of a purely phonological constraint in a listener's native language can also elicit the brain's automatic change-detection response. The MMN differed between Finnish and Estonian listeners, conditions being equal except for the native language of the listeners. We used two experimental conditions: synthetic vowels in isolation and the same vowels embedded in a pseudo-word context. MMN responses to isolated vowels were similar for Finns and Estonians, while the same vowels in a pseudoword context elicited different MMN patterns depending on the listener's mother tongue.
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| 2. |
- Alsiö, Johan, et al.
(författare)
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Motivation for sucrose in sated rats is predicted by low anxiety-like behavior
- 2009
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Ingår i: Neuroscience Letters. - : Elsevier. - 0304-3940 .- 1872-7972. ; 454:3, s. 193-197
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Tidskriftsartikel (refereegranskat)abstract
- Anxiety has been implicated in obesity and in the overconsumption of highly palatable foods such as those high in fat, sugar, or both. Also, the novelty-seeking trait has been associated with failure in weight-loss programs. The aim of this study was to investigate the associations of experimental anxiety and the self-administration of sucrose and high fat pellets in non-food deprived rats across different operant schedules. Male Wistar rats were subjected to the elevated plus-maze test (EPM) of anxiety-like behavior. The rats were tested for fixed ratio 5 (FR5) and progressive ratio (PR) operant responding for 50% sucrose, 95% sucrose, and high-fat pellets. PR active lever press response for 95% sucrose, but not the other pellet types, was correlated to % time spent on open arms (P=0.019) in the EPM. On the FR5 schedule, activity (closed arm entries) was correlated to the self-administration of 50% sucrose (P=0.027) and high-fat (P=0.002). This indicates an association of novelty-induced activity and self-administration of palatable food in sated rats, as well as a specific association of PR lever press response for 95% sucrose and low anxiety-like behavior. It has been argued that such active lever press response on PR may be interpreted as craving for the reinforcer; thus, our findings indicate an inverse relationship of experimental anxiety and craving for sucrose. This connection may have implications for human situations, since anxiety and novelty-seeking have been associated with obesity and failure in weight-loss programs.
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| 3. |
- Armstrong, Stephanie J, et al.
(författare)
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Laminin activates NF-kappaB in Schwann cells to enhance neurite outgrowth.
- 2008
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Ingår i: Neuroscience Letters. - : Elsevier BV. - 0304-3940 .- 1872-7972. ; 439:1, s. 42-6
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Tidskriftsartikel (refereegranskat)abstract
- Extracellular matrix (ECM) molecules and Schwann cells (SCs) are important components of peripheral nerve regeneration. In this study, the role of the transcription factor nuclear factor kappa B (NF-kappaB) in SC activation in response to laminin and the subsequent effect on in vitro neurite outgrowth was investigated. Immunocytochemistry and Western blot analysis showed that compared with poly-d-lysine (PDL), laminin enhanced the phosphorylation of IkappaB and p65 NF-kappaB signalling proteins in SCs. Phospho NF-kappaB-p65 was localised to the nucleus indicating activation of NF-kappaB. To assess the functional effect of NF-kappaB activation, SCs plated on PDL or laminin were pre-treated with NF-kappaB inhibitors, 6-amino-4-(4-phenoxyphenylethylamino)quinazoline (QNZ) or Z-leu-leu-leu-CHO (MG-132) before NG108-15 neuronal cells were seeded on the SC monolayer. After 24h co-culture in the absence of inhibitors, SCs seeded on laminin enhanced the mean number and length of neurites extended by NG108-15 cells (1.87+/-0.13 neurites; 238.74+/-8.53microm) compared with those cultured in the presence of SCs and PDL (1.26+/-0.07 neurites; 157.57+/-9.80microm). At 72h, neurite length had further increased to 321.83+/-6.60microm in the presence of SCs and laminin. Inhibition of NF-kappaB completely abolished the effect of laminin on SC evoked neurite outgrowth at 24h and reduced the enhancement of neurite length by over 60% at 72h. SC proliferation was unaffected by NF-kappaB inhibition suggesting that the NF-kappaB signalling pathway plays a discrete role in the activation of SCs and their neurotrophic potential.
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| 4. |
- Belin, Andrea Carmine, et al.
(författare)
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Association study of two genetic variants in mitochondrial transcription factor A (TFAM) in Alzheimer's and Parkinson's disease.
- 2007
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Ingår i: Neuroscience letters. - : Elsevier BV. - 0304-3940. ; 420:3, s. 257-62
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Tidskriftsartikel (refereegranskat)abstract
- Mitochondrial (mt) dysfunction has been implicated in Alzheimer's (AD) and Parkinson's disease (PD). Mitochondrial transcription factor A (TFAM) is needed for mtDNA maintenance, regulating mtDNA copy number and is absolutely required for transcriptional initiation at mtDNA promoters. Two genetic variants in TFAM have been reported to be associated with AD in a Caucasian case-control material collected from Germany, Switzerland and Italy. One of these variants was reported to show a tendency for association with AD in a pooled Scottish and Swedish case-control material and the other variant was reported to be associated with AD in a recent meta-analysis. We investigated these two genetic variants, rs1937 and rs2306604, in an AD and a PD case-control material, both from Sweden and found significant genotypic as well as allelic association to marker rs2306604 in the AD case-control material (P=0.05 and P=0.03, respectively), where the A-allele appears to increase risk for developing AD. No association was observed for marker rs1937. We did not find any association in the PD case-control material for either of the two markers. The distribution of the two-locus haplotype frequencies (based on rs1937 and rs2306604) did not differ significantly between affected individuals and controls in the two sample sets. However, the global P-value for haplotypic association testing indicated borderline association in the AD sample set. Our data suggests that the rs2306604 A-allele could be a moderate risk factor for AD, which is supported by the recent meta-analysis.
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| 5. |
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| 6. |
- Birgner, Carolina, et al.
(författare)
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Altered extracellular levels of DOPAC and HVA in the rat nucleus accumbens shell in response to sub-chronic nandrolone administration and a subsequent amphetamine challenge
- 2007
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Ingår i: Neuroscience Letters. - : Elsevier BV. - 0304-3940 .- 1872-7972. ; 412:2, s. 168-172
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Tidskriftsartikel (refereegranskat)abstract
- Associated with acts of violence and polydrug use, abuse of anabolic androgenic steroids (AAS) is an increasing problem in society. The aim of the present study was to elucidate whether sub-chronic treatment with the AAS nandrolone decanoate affects dopamine release and dopamine metabolism in the rat nucleus accumbens shell, before and after an amphetamine challenge. Male Sprague–Dawley rats received daily i.m. injections of nandrolone decanoate (15 mg/kg) or vehicle for 14 days. On day 15, the animals were anaesthetized and a microdialysis probe was implanted into the nucleus accumbens shell. Extracellular fluid was collected 1 h before and 3 h after a single amphetamine injection (5 mg/kg). The samples were then analyzed regarding the content of dopamine, and its metabolites 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA), using HPLC with electrochemical detection. Two weeks of nandrolone decanoate administration caused a significant decrease of the basal DOPAC and HVA levels, which remained low during the first hour following the amphetamine challenge. Dopamine levels did not differ significantly between groups, neither after the nandrolone pre-treatment nor the amphetamine challenge. In conclusion, these novel findings indicate that AAS alter the metabolism of dopamine in a brain region involved in the development of drug dependence.
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| 7. |
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| 8. |
- Blennow, Kaj, 1958, et al.
(författare)
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Longitudinal stability of CSF biomarkers in Alzheimer's disease
- 2007
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Ingår i: Neuroscience Letters. - : Elsevier BV. - 0304-3940 .- 1872-7972. ; 419:1, s. 18-22
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Tidskriftsartikel (refereegranskat)abstract
- Biomarker levels in cerebrospinal fluid (CSF) may serve as surrogate markers for treatment efficacy in clinical trials of disease-modifying drugs against Alzheimer's disease (AD). A prerequisite, however, is that the marker is sufficiently stable over time in individual patients. Here, we tested the stability of the three established CSF biomarkers for AD, total tau (T-tau), tau phosphorylated at threonine 181 (P-tau181) and the 42 amino acid isoform of β-amyloid (Aβ42), over 6 months in a cohort of AD patients on stable treatment with acetylcholinesterase (AChE) inhibitors. Fifty-three patients completed the study, 29 men and 24 women, mean age (±S.D.) 76.1 ± 7.9 years. Mean levels of CSF biomarkers were very stable between baseline and endpoint, with coefficients of variation (CVs) of 4.4–6.1%. Intra-individual biomarker levels at baseline and endpoint were also highly correlated with Pearson r-values above 0.95 (p < 0.0001), for all three markers. We conclude that T-tau, P-tau and Aβ42 concentrations in CSF are remarkably stable over a 6-month period in individual AD patients. This suggest that these biomarkers may have a potential to identify and monitor very minor biochemical changes induced by treatment, and thus support their possible usefulness as surrogate markers in clinical trials with drug candidates with disease-modifying potential, such as secretase inhibitors, Aβ immunotherapy and tau phosphorylation inhibitors.
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