| 1. |
- Benjaminsson, Simon, et al.
(författare)
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Adaptive sensor drift counteraction by a modular neural network
- 2010
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Ingår i: Neuroscience research. - : Elsevier BV. - 0168-0102 .- 1872-8111. ; 68, s. E212-E212
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- The response properties of sensors such as electronic noses vary in time due to internal or environmental factors. Recalibration is often costly or technically infeasible, which is why algorithms aimed at addressing the sensor drift problem at the data processing level have been developed. These falls in two categories: The pre-processing approaches, such as component correction [1], try to extract the direction and amount of drift in the training data and remove the drift component during operation. Adaptive algorithms, such as the self-organizing map [2], try to counteract the drift during runtime by adjusting the network to the incoming data.We have previously suggested a modular neural network architecture as a model of cortical layer 4 [3]. Here we show how it quite well can handle the sensor drift problem in chemosensor data. It creates a distributed and redundant code suitable for a noisy and drifting environment. A feature extraction layer governed by competitive learning allows for network adaptation during runtime. In addition, training data can be utilized to create a prediction of the underlying drift to further improve the network performance. Hence, we attempt to combine the two aforementioned methodological categories into one network model.The capabilities of the proposed network are demonstrated on surrogate data as well as real-world data collected from an electronic nose.
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| 2. |
- Bezard, Erwan, et al.
(författare)
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Anti-dyskinetic effect of anpirtoline in animal models of L-DOPA-induced dyskinesia
- 2013
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Ingår i: Neuroscience Research. - : Elsevier BV. - 0168-0102. ; 77:4, s. 242-246
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Tidskriftsartikel (refereegranskat)abstract
- The serotonin system has emerged as a potential target for anti-dyskinetic therapy in Parkinson's disease. In fact, serotonin neurons can convert L-DOPA into dopamine, and mediate its synaptic release. However, they lack a feedback control mechanism able to regulate synaptic dopamine levels, which leads to un-physiological stimulation of post-synaptic striatal dopamine receptors. Accordingly, drugs able to dampen the activity of serotonin neurons can suppress L-DOPA-induced dyskinesia in animal models of Parkinson's disease. Here, we investigated the ability of the 5-HT1A/1B receptor agonist anpirtoline to counteract LDOPA-induced dyskinesia in L-DOPA-primed 6-OHDA-lesioned rats and MPTP-treated macaques. Results suggest that anpirtoline dose-dependently reduced dyskinesia both in rats and monkeys; however, the effect in MPTP-treated macaques was accompanied by a worsening of the Parkinson's disease score at significantly effective doses (1.5 and 2.0 mg/kg). At a lower dose (0.75 mg/ kg), anpirtoline markedly reduced dyskinesia in 4 out of 5 subjects, but statistical significance was prevented by the presence of a non-responsive subject. These results provide further evidence that the serotonin neurons contribute both to the pro-dyskinetic effect of L-DOPA and to its therapeutic efficacy in the rat and monkey models of Parkinson's disease. (c) 2013 Elsevier Ireland Ltd and the Japan Neuroscience Society. All rights reserved.
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| 3. |
- Chauhan, Mayank, et al.
(författare)
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Muscle-specific regulation of the mTOR signaling pathway in MuSK antibody seropositive (MuSK plus ) experimental autoimmune Myasthenia gravis (EAMG)
- 2013
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Ingår i: Neuroscience research. - : Elsevier BV. - 0168-0102 .- 1872-8111. ; 77:1-2, s. 102-109
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Tidskriftsartikel (refereegranskat)abstract
- Myasthenia gravis (MG) patients with antibodies against muscle specific tyrosine kinase (MuSK+) typically present focal fatigue and atrophy of the facial and bulbar muscles, including the masseter muscle, whereas leg muscles often are clinically spared. This study addresses the regulation of the mTOR signaling pathway in the masseter muscle versus the leg muscle tibialis anterior (TA). We analyzed muscle morphology, protein levels of mTOR components as well as atrogenes and mitochondrial markers in these muscles of healthy control mice and mice with different clinical severity grades of MuSK+ experimental autoimmune MG (EAMG). Protein levels of mTOR components were reduced in the atrophic masseter muscle of MuSK+ EAMG mice, whereas enhanced accumulation of mTOR components was observed in the TA muscles. Two other muscles: omohyoid and soleus showed intermediate spectra. In conclusion, the anabolic mTOR signaling pathway is differentially regulated even in muscles with the same activity pattern in the same neuromuscular disease. This could in part explain the clinical phenotype in MuSK+ EAMG as well as in muscular dystrophies.
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| 4. |
- Forsman, Lea J, et al.
(författare)
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Differences in regional brain volume related to the extraversion–introversion dimension : a voxel based morphometry study
- 2012
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Ingår i: Neuroscience research. - : Elsevier. - 0168-0102 .- 1872-8111. ; 72:1, s. 59-67
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Tidskriftsartikel (refereegranskat)abstract
- Extraverted individuals are sociable, behaviorally active, and happy. We report data from a voxel based morphometry study investigating, for the first time, if regional volume in gray and white matter brain regions is related to extraversion. For both gray and white matter, all correlations between extraversion and regional brain volume were negative, i.e. the regions were larger in introverts. Gray matter correlations were found in regions that included the right prefrontal cortex and the cortex around the right temporo–parietal junction – regions that are known to be involved in behavioral inhibition, introspection, and social-emotional processing, e.g. evaluation of social stimuli and reasoning about the mental states of others. White matter correlations extended from the brainstem to widespread cortical regions, and were largely due to global effects, i.e. a larger total white matter volume in introverts. We speculate that these white matter findings may reflect differences in ascending modulatory projections affecting cortical regions involved in behavioral regulation.
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| 5. |
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| 6. |
- Huang, Fen-Sheng, 1961, et al.
(författare)
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Bidirectional synaptic plasticity in response to single or paired pulse activation of NMDA receptors.
- 2010
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Ingår i: Neuroscience research. - : Elsevier BV. - 1872-8111 .- 0168-0102. ; 67:2, s. 108-116
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Tidskriftsartikel (refereegranskat)abstract
- It is still incompletely known how NMDA receptors (NMDA-R) regulate bidirectional synaptic plasticity. We examined this issue by an experimental protocol in which paired pulse stimulation (PPS) with 50ms interstimulus interval and basal frequency of 0.1Hz was applied to CA1 area of rat hippocampal slices during low Mg(2+) perfusion. Under blockade of NMDA-Rs by AP5, PPS for 12-60min led to only a minor depression. In contrast, when PPS was applied in the absence of AP5, there was a prominent short-term potentiation (STP), mainly of AMPA-R mediated responses, with peak at 1min and lasting 10-15min. The STP was followed by a slowly developing long-term depression (LTD). Applying AP5 during the STP, converted it to a stable increase relative to the control pathway. Following peak STP, plasticity was controlled in a composite manner. Whereas the initial decay was counteracted by NMDA-R activation, the following LTD was dependent on such activation. Our data suggest that synaptic changes do not only depend on the instantaneous, NMDA-dependent Ca(2+) concentration in the dendritic spine, but are also influenced by prior induction events. In addition to NMDA-R driven processes, passive relaxation contributes to the synaptic plasticity and in some cases outbalances the active control.
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| 7. |
- Larsson, Linda, et al.
(författare)
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Ultra-high olfactory sensitivity for the human sperm-attractant aromaticaldehyde bourgeonal in CD-1 mice
- 2011
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Ingår i: Neuroscience research. - : Elsevier Ireland Ltd and the Japan Neuroscience Society. - 0168-0102 .- 1872-8111. ; 71:4, s. 355-360
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Tidskriftsartikel (refereegranskat)abstract
- Recent studies have shown that certain aromatic aldehydes are ligands for olfactory receptors expressedin mammalian sperm cells and induce sperm chemotaxis. Using a conditioning paradigm, the olfactorysensitivity of five CD-1 mice for seven aromatic aldehydes was investigated. With all seven stimuli, themice discriminated concentrations as low as 0.01 ppm (parts per million) from the solvent, and withbourgeonal the animals even detected concentrations as low as 0.1 ppq (parts per quadrillion) whichconstitutes the lowest olfactory detection threshold value reported in this species so far. The presence ofa tertiary butyl group in para-position (relative to the functional aldehyde group) combined with a lack ofan additional alkyl group next to the functional aldehyde group may be responsible for the extraordinarysensitivity of the mice for bourgeonal.
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| 8. |
- Mattsson, Niklas, 1979, et al.
(författare)
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Converging molecular pathways in human neural development and degeneration.
- 2010
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Ingår i: Neuroscience research. - : Elsevier BV. - 1872-8111 .- 0168-0102. ; 66:3, s. 330-2
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Tidskriftsartikel (refereegranskat)abstract
- Animal studies suggest that phosphorylation of microtubule-associated protein tau is a physiological way of destabilizing axons in the developing brain, promoting synaptic plasticity, while in the adult human brain tau phosphorylation is a specific sign of Alzheimer's disease. We here show, for the first time, that newborn human infants have extremely high levels of phosphorylated tau in their cerebrospinal fluid, and that these levels decrease during the first years of life. Tau phosphorylation in Alzheimer's disease may be a physiological response to Alzheimer-associated synaptotoxicity.
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| 10. |
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