| 21. |
- Bergquist, Filip, 1970, et al.
(författare)
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Influence of R-type (Cav2.3) and t-type (Cav3.1-3.3) antagonists on nigral somatodendritic dopamine release measured by microdialysis.
- 2003
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Ingår i: Neuroscience. - 0306-4522. ; 120:3, s. 757-64
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Tidskriftsartikel (refereegranskat)abstract
- The release of dopamine from soma and dendrites of dopaminergic neurons in substantia nigra has been reported to be calcium-dependent, but it remains to be determined which calcium channels mediate this effect. We have used in vivo microdialysis in rat substantia nigra and striatum to investigate the effect of Ca(v)3.1-3.3 (T-type) and Ca(v)2.3 (R-type) calcium channel antagonists on somatodendritic and terminal dopamine release. Local reverse dialysis administration of 0.1-10 microM of the Ca(v)2.3 inhibitor SNX-482, or 100 microM of mibefradil, decreased the concentrations of dopamine and its metabolites in dialysate from substantia nigra, whereas 1 microM mibefradil or 40-80 microM nickel(II) induced an increase in nigral dialysate dopamine concentrations. Dopamine concentrations in striatal dialysates were decreased only by 10 microM of SNX-482 or 100 microM of mibefradil. Nickel(II) induced an increase in striatal dialysate dopamine concentration similar to that in substantia nigra. The results indicate a role for Ca(v)2.3 (R-type) voltage sensitive calcium channels in the calcium dependency of somatodendritic dopamine release, but argue against a calcium dependency mediated substantially by Ca(v)3.1-3.3 (T-type) channels.
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| 22. |
- Bergquist, Filip, 1970, et al.
(författare)
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Somatodendritic dopamine release in rat substantia nigra influences motor performance on the accelerating rod.
- 2003
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Ingår i: Brain research. - 0006-8993. ; 973:1, s. 81-91
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Tidskriftsartikel (refereegranskat)abstract
- The physiological role of somatodendritic dopamine release in the rat substantia nigra was evaluated with a combination of dual probe microdialysis and simultaneous motor performance tests on an accelerating rod. Three main findings support a modulating influence of somatodendritic dopamine release on motor coordination. (1) The rod performance tests were associated with an increase in extracellular dopamine but not 5-hydroxytryptamine concentrations in substantia nigra and with increases in both dopamine and 5-hydroxytryptamine concentrations in the striatum. (2) Nigral application of dopamine antagonists without intrinsic activity resulted in changed performances on the accelerating rod. The response to nigral perfusion with low concentrations (0.1, 1.0 microM) of the D(2)/D(3)-antagonist raclopride consisted of an impairment in rod performance to 63% of the pre-perfusion performance. Higher concentrations (10, 100 microM), however, were not associated with impaired rod performance, but with increased striatal dopamine concentrations. Perfusion of the substantia nigra with 1, 10 and 100 microM of the D(1)/D(5)-antagonist SCH 23390 dose-dependently impaired rod performance. SCH 23390 consistently increased dopamine and 5-hydroxytryptamine concentrations in substantia nigra but did not change the dialysate in the striatum. (3) In unilaterally 6-hydroxydopamine-lesioned rats, a dose-dependent improvement in rod performance was observed during perfusion of the substantia nigra with the non-selective dopamine agonist apomorphine.
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| 23. |
- Buervenich, Silvia, et al.
(författare)
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A rare truncating mutation in ADH1C (G78Stop) shows significant association with Parkinson disease in a large international sample.
- 2005
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Ingår i: Archives of neurology. - : American Medical Association (AMA). - 0003-9942. ; 62:1, s. 74-8
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Alcohol dehydrogenases (ADHs) may be involved in the pathogenesis of neurodegenerative disorders because of their multiple roles in detoxification pathways and retinoic acid synthesis. In a previous study, significant association of an ADH class IV allele with Parkinson disease (PD) was found in a Swedish sample. PATIENTS: The previously associated single-nucleotide polymorphism plus 12 further polymorphisms in the ADH cluster on human chromosome 4q23 were screened for association in an extension of the original sample that now included 123 Swedish PD patients and 127 geographically matched control subjects. A rare nonsense single-nucleotide polymorphism in ADH1C (G78stop, rs283413) was identified in 3 of these patients but in no controls. To obtain sufficient power to detect a possible association of this rare variant with disease, we screened a large international sample of 1076 PD patients of European ancestry and 940 matched controls. RESULTS: The previously identified association with an ADH class IV allele remained significant (P<.02) in the extended Swedish study. Furthermore, in the international collaboration, the G78stop mutation in ADH1C was found in 22 (2.0%) of the PD patients but only in 6 controls (0.6%). This association was statistically significant (chi(2)(1) = 7.5; 2-sided P = .007; odds ratio, 3.25 [95% confidence interval, 1.31-8.05]). In addition, the G78stop mutation was identified in 4 (10.0%) of 40 Caucasian index cases with PD with mainly hereditary forms of the disorder. CONCLUSION: Findings presented herein provide further evidence for mutations in genes encoding ADHs as genetic risk factors for PD.
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| 24. |
- Carmine Belin, Andrea, et al.
(författare)
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Leucine-rich repeat kinase 2 (LRRK2) mutations in a Swedish Parkinson cohort and a healthy nonagenarian.
- 2006
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Ingår i: Movement disorders : official journal of the Movement Disorder Society. - : Wiley. - 0885-3185. ; 21:10, s. 1731-4
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Tidskriftsartikel (refereegranskat)abstract
- Specific variants of Leucine-rich repeat kinase 2 (LRRK2) have been shown to associate with Parkinson's disease (PD). Several mutations have been found in PD populations from different parts of the world. We investigated the occurrence of three mutations (R1441G/C/H, G2019S, and I2020T) in our Swedish case-control material and identified four carriers of the G2019S mutation in 284 PD cases and 1 95-year-old carrier in 305 controls. The other two variants were absent in our material. We conclude that the LRRK2 G2019S mutation constitutes a significant factor for PD in the Swedish population and that it is not completely penetrant.
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| 25. |
- Carmine Belin, Andrea, et al.
(författare)
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S18Y in ubiquitin carboxy-terminal hydrolase L1 (UCH-L1) associated with decreased risk of Parkinson's disease in Sweden.
- 2007
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Ingår i: Parkinsonism & related disorders. - : Elsevier BV. - 1353-8020. ; 13:5, s. 295-8
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Tidskriftsartikel (refereegranskat)abstract
- Ubiquitin carboxy-terminal hydrolase L1 (UCH-L1) is a neuron-specific enzyme that removes ubiquitin from the C-terminal end of substrates and a component of the ubiquitin-proteasome system. A protective effect of a UCH-L1 variant, S18Y, was suggested since the common variant was found to be inversely associated with sporadic Parkinson's disease (PD). We investigated the association of S18Y in our Swedish PD material. The tyrosine variant was significantly inversely associated with PD (P=0.049) and with a low age of onset (50 years) (P=0.017) in the case-control material, supporting the hypothesis of a protective function.
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| 26. |
- Dickson, Suzanne L., 1966, et al.
(författare)
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The glucagon-like peptide 1 (GLP-1) analogue, exendin-4, decreases the rewarding value of food: a new role for mesolimbic GLP-1 receptors.
- 2012
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Ingår i: The Journal of neuroscience : the official journal of the Society for Neuroscience. - 1529-2401. ; 32:14, s. 4812-20
-
Tidskriftsartikel (refereegranskat)abstract
- The glucagon-like peptide 1 (GLP-1) system is a recently established target for type 2 diabetes treatment. In addition to regulating glucose homeostasis, GLP-1 also reduces food intake. Previous studies demonstrate that the anorexigenic effects of GLP-1 can be mediated through hypothalamic and brainstem circuits which regulate homeostatic feeding. Here, we demonstrate an entirely novel neurobiological mechanism for GLP-1-induced anorexia in rats, involving direct effects of a GLP-1 agonist, Exendin-4 (EX4) on food reward that are exerted at the level of the mesolimbic reward system. We assessed the impact of peripheral, central, and intramesolimbic EX4 on two models of food reward: conditioned place preference (CPP) and progressive ratio operant-conditioning. Food-reward behavior was reduced in the CPP test by EX4, as rats no longer preferred an environment previously paired to chocolate pellets. EX4 also decreased motivated behavior for sucrose in a progressive ratio operant-conditioning paradigm when administered peripherally. We show that this effect is mediated centrally, via GLP-1 receptors (GLP-1Rs). GLP-1Rs are expressed in several key nodes of the mesolimbic reward system; however, their function remains unexplored. Thus we sought to determine the neurobiological substrates underlying the food-reward effect. We found that the EX4-mediated inhibition of food reward could be driven from two key mesolimbic structures-ventral tegmental area and nucleus accumbens-without inducing concurrent malaise or locomotor impairment. The current findings, that activation of central GLP-1Rs strikingly suppresses food reward/motivation by interacting with the mesolimbic system, indicate an entirely novel mechanism by which the GLP-1R stimulation affects feeding-oriented behavior.
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| 27. |
- Eriksson, Elias, 1956, et al.
(författare)
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Escitalopram Administered in the Luteal Phase Exerts a Marked and Dose-Dependent Effect in Premenstrual Dysphoric Disorder.
- 2008
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Ingår i: Journal of clinical psychopharmacology. - 0271-0749. ; 28:2, s. 195-202
-
Tidskriftsartikel (refereegranskat)abstract
- This is the first placebo-controlled trial evaluating the efficacy of the selective serotonin reuptake inhibitor (SSRI), escitalopram, in the treatment of premenstrual dysphoric disorder (PMDD). Women with PMDD (intention-to-treat population, n = 151) were treated intermittently for 3 months, during luteal phases only, with 10 mg/d escitalopram, 20 mg/d escitalopram, or placebo. Escitalopram was found to exert a marked and a dose-dependent symptom-reducing effect, 20 mg/d being clearly superior to 10 mg/d. Although the primary outcome parameter, that is, the sum of the symptoms irritability, depressed mood, tension, and affective lability, was decreased by 90% with 20 mg/d escitalopram, the effect of active treatment on breast tenderness, food craving, and lack of energy was more modest and not significantly different from that of placebo; this outcome supports our previous assumption that the former symptoms are more inclined to respond to intermittent administration of an SSRI than are the latter. Although the placebo response was high, the difference between the placebo group and the 20-mg/d escitalopram group with respect to the percentage of subjects displaying 80% or greater reduction in the rating of the cardinal symptom of PMDD, that is, irritability, was considerable: 30% versus 80%. Adverse events were those normally reported in SSRI trials, such as nausea and reduced libido, and were not more common in patients given 20 mg/d of escitalopram than in patients given the lower dose. This study supports the usefulness of escitalopram for the treatment of PMDD and sheds further light on how different components of this syndrome are differently influenced by intermittent administration of an SSRI.
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| 28. |
- Fardell, Camilla, et al.
(författare)
-
S100B polymorphisms are associated with age of onset of Parkinson's disease
- 2018
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Ingår i: Bmc Medical Genetics. - : Springer Science and Business Media LLC. - 1471-2350. ; 19:42
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Tidskriftsartikel (refereegranskat)abstract
- Background: In this study we investigated the association between SNPs in the S100B gene and Parkinson's disease (PD) in two independent Swedish cohorts. The SNP rs9722 has previously been shown to be associated with higher S100B concentrations in serum and frontal cortex in humans. S100B is widely expressed in the central nervous system and has many functions such as regulating calcium homeostasis, inflammatory processes, cytoskeleton assembly/disassembly, protein phosphorylation and degradation, and cell proliferation and differentiation. Several of these functions have been suggested to be of importance for the pathophysiology of PD. Methods: The SNPs rs9722, rs2239574, rs881827, rs9984765, and rs1051169 of the S100B gene were genotyped using the KASPar (R) PCR SNP genotyping system in a case-control study of two populations (431 PD patients and 465 controls, 195 PD patients and 378 controls, respectively). The association between the genotype and allelic distributions and PD risk was evaluated using Chi-Square and Cox proportional hazards test, as well as logistic regression. Linear regression and Cox proportional hazards tests were applied to assess the effect of the rs9722 genotypes on age of disease onset. Results: The S100B SNPs tested were not associated with the risk of PD. However, in both cohorts, the T allele of rs9722 was significantly more common in early onset PD patients compared to late onset PD patients. The SNP rs9722 was significantly related to age of onset, and each T allele lowered disease onset with 4.9 years. In addition, allelic variants of rs881827, rs9984765, and rs1051169, were significantly more common in early-onset PD compared to late-onset PD in the pooled population. Conclusions: rs9722, a functional SNP in the 3'-UTR of the S100B gene, was strongly associated with age of onset of PD.
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| 29. |
- Francardo, Veronica, et al.
(författare)
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Impact of the lesion procedure on the profiles of motor impairment and molecular responsiveness to L-DOPA in the 6-hydroxydopamine mouse model of Parkinson's disease.
- 2011
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Ingår i: Neurobiology of disease. - : Elsevier BV. - 1095-953X .- 0969-9961. ; 42:3, s. 327-40
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Tidskriftsartikel (refereegranskat)abstract
- 6-Hydroxydopamine (6-OHDA) lesions are being used in the mouse for basic research on Parkinson's disease and L-DOPA-induced dyskinesia. We set out to compare unilateral lesion models produced by intrastriatal or intramesencephalic injections of a fixed 6-OHDA concentration (3.2 μg/μl) in C57BL/6 mice. In the first experiment, toxin injections were performed either at two striatal coordinates (1 or 2 μl per site, termed "striatum(2 × 1 μl)" and "striatum(2 × 2 μl)" models), in the medial forebrain bundle (MFB), or in the substantia nigra pars compacta (SN) (1 μl per site). All the four lesion models produced significant forelimb use asymmetry, but spontaneous turning asymmetry only occurred in the MFB and striatum(2 × 2 μl) models. After the behavioral studies, the induction of phosphorylated extracellular signal-regulated kinases 1 and 2 (pERK1/2) by acute L-DOPA (30 mg/kg) was used as a marker of post-synaptic supersensitivity. Striatal pERK1/2 expression was sparse in the SN and striatum(2 × 1 μl) groups, but pronounced in the striatum(2 × 2 μl) and MFB-lesioned mice. In further experiments, mice with MFB and striatal(2 × 2 μl) lesions were used to compare behavioral and molecular responses to chronic L-DOPA treatment (12 days at 3 and 6 mg/kg/day). Maximally severe abnormal involuntary movements (AIMs) occurred in all MFB-lesioned mice, whereas only 35% of the mice with striatal lesions developed dyskinesia. Striatal tissue levels of dopamine were significantly lower in the dyskinetic animals (both MFB and striatum(2 × 2 μl) groups) in comparison with the non-dyskinetic ones. Noradrenaline levels were significantly reduced only in MFB lesioned animals and did not differ among the dyskinetic and non-dyskinetic cases with striatal lesions. In all groups, the L-DOPA-induced AIM scores correlated closely with the number of cells immunoreactive for tyrosine hydroxylase or FosB/∆FosB in the striatum. In conclusion, among the four lesion procedures examined here, only the MFB and striatum(2 × 2 μl) models yielded a degree of dopamine denervation sufficient to produce spontaneous postural asymmetry and molecular supersensitivity to L-DOPA. Both lesion models are suitable to reproduce L-DOPA-induced dyskinesia, although only MFB lesions yield a pronounced and widespread expression of post-synaptic supersensitivity markers in the striatum.
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| 30. |
- Francardo, Veronica, et al.
(författare)
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Pharmacological stimulation of sigma-1 receptors has neurorestorative effects in experimental parkinsonism
- 2014
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Ingår i: Brain. - : Oxford University Press (OUP). - 0006-8950 .- 1460-2156. ; 137, s. 1998-2014
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Tidskriftsartikel (refereegranskat)abstract
- Sigma-1 receptor ligands may have neuroprotective and neurorestorative properties. In a mouse model of parkinsonism, Francardo et al. show that chronic treatment with the sigma-1 receptor agonist PRE-084 increases the density of striatal dopaminergic fibres and improves forelimb use. Boosting sigma-1 receptor activity may have disease-modifying effects in ParkinsonA ' s disease.The sigma-1 receptor, an endoplasmic reticulum-associated molecular chaperone, is attracting great interest as a potential target for neuroprotective treatments. We provide the first evidence that pharmacological modulation of this protein produces functional neurorestoration in experimental parkinsonism. Mice with intrastriatal 6-hydroxydopamine lesions were treated daily with the selective sigma-1 receptor agonist, PRE-084, for 5 weeks. At the dose of 0.3 mg/kg/day, PRE-084 produced a gradual and significant improvement of spontaneous forelimb use. The behavioural recovery was paralleled by an increased density of dopaminergic fibres in the most denervated striatal regions, by a modest recovery of dopamine levels, and by an upregulation of neurotrophic factors (BDNF and GDNF) and their downstream effector pathways (extracellular signal regulated kinases 1/2 and Akt). No treatment-induced behavioural-histological restoration occurred in sigma-1 receptor knockout mice subjected to 6-hydroxydopamine lesions and treated with PRE-084. Immunoreactivity for the sigma-1 receptor protein was evident in both astrocytes and neurons in the substantia nigra and the striatum, and its intracellular distribution was modulated by PRE-084 (the treatment resulted in a wider intracellular distribution of the protein). Our results suggest that sigma-1 receptor regulates endogenous defence and plasticity mechanisms in experimental parkinsonism. Boosting the activity of this protein may have disease-modifying effects in Parkinson's disease.
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