| 1. |
- Andersen, Søren S. L.
(författare)
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Real time large scale in vivo observations reveal intrinsic synchrony, plasticity and growth cone dynamics of midline crossing axons at the ventral floor plate of the zebrafish spinal cord
- 2019
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Ingår i: Journal of Integrative Neuroscience. - : IMR Press. - 0219-6352 .- 1757-448X. ; 18:4, s. 351-368
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Tidskriftsartikel (refereegranskat)abstract
- How axons are wiring the vertebrate spinal cord has in particular been studied at the ventral floor plate using fixed samples or looking at single growing axons with various microscopy techniques. Thereby may remain hidden important live organismal scale information concerning dynamics and concurrent timing of the many axons simultaneously crossing the floor plate. Here then, applying light-sheet microscopy, axonal growth and guidance at the floor plate are followed in vivo in real time at high resolution along several hundred micrometers of the zebrafish spinal cord by using an interneuron expressing GFP as a model axon. The commissural axons are observed crossing the ventral floor plate midline perpendicularly at about 20 microns/h and in a manner dependent on the Robo3 receptor. Commissural growth rate reaches a minimum at the midline, confirming previous observations. Ipsilateral axons extend concurrently, at three to six times higher growth rates. At guidance points, commissural axons are seen to decrease their growth rate and growth cones increase in size. Commissural filopodia appear to interact with the nascent neural network, and thereby trigger immediate plastic and reversible sinusoidal-shaped bending movements of neighboring commissural shafts. A simple protocol isolating single neuronal cells from the spinal cord is developed to facilitate further molecular characterization. The recordings show the strikingly stereotyped spatio-temporal control that governs midline crossing. The live observations give renewed perspective on the mechanisms of axonal guidance in the spinal cord that provide for a discussion of the current distinction between diffusible long-range versus substrate-bound short-range guidance cues.
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| 2. |
- Dale, Caitlin, et al.
(författare)
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Aberrant callosal morphology in ex-smokers
- 2022
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Ingår i: Journal of Integrative Neuroscience. - : IMR Press. - 0219-6352 .- 1757-448X. ; 21:4
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Tidskriftsartikel (refereegranskat)abstract
- Background: Cigarette smoking is associated with widespread structural alterations in both brain hemispheres as well as of the corpus callosum (i.e., the brain???s main interhemispheric white matter pathway). While similar hemispheric alterations have also been reported in ex-smokers, no study has yet examined the corpus callosum in ex-smokers.Methods: We compared callosal morphology in a sample of 107 ex-smokers (57 males/50 females) and 193 non-smokers (73 males/120 females), aged between 42 and 97 years. More specifically, we measured the total callosal area as well as seven callosal subregions using the Witelson parcellation scheme.Results: At uncorrected levels, we detected significantly smaller callosal areas in ex-smokers than in non-smokers within the posterior midbody, genu, and isthmus (albeit the latter only on a trend level). When applying corrections for multiple comparisons, only the effect within the posterior midbody remained significant.Conclusions: Our findings suggest a weaker interhemispheric connectivity in ex-smokers compared to non-smokers, specifically between frontal and temporal areas.
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| 3. |
- Edin, Fredrik, et al.
(författare)
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Fronto-Pariatal connection asymmetry regulates working memory distractibility
- 2007
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Ingår i: Journal of Integrative Neuroscience. - 0219-6352 .- 1757-448X. ; 6:4, s. 567-596
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Tidskriftsartikel (refereegranskat)abstract
- Recent functional magnetic resonance imaging studies demonstrate that increased task-related neural activity in parietal and frontal cortex during development and training is positively correlated with improved visuospatial working memory (vsWM) performance. Yet, the analysis of the corresponding underlying functional reorganization of the fronto-parietal network has received little attention. Here, we perform an integrative experimental and computational analysis to determine the effective balance between the superior frontal sulcus (SFS) and intraparietal sulcus (IPS) and their putative role(s) in protecting against distracters. To this end, we performed electroencephalographic (EEG) recordings during a vsWM task. We utilized a biophysically based computational cortical network model to analyze the effects of different neural changes in the underlying cortical networks on the directed transfer function (DTF) and spiking activity. Combining a DTF analysis of our EEG data with the DTF analysis of the computational model, a directed strong SFS → IPS network was revealed. Such a configuration offers protection against distracters, whereas the opposite is true for strong IPS → SFS connections. Our results therefore suggest that the previously demonstrated improvement of vsWM performance during development could be due to a shift in the control of the effective balance between the SFS-IPS networks.
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| 4. |
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| 5. |
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| 6. |
- Han, Peng, et al.
(författare)
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Moderate-intensity treadmill exercise regulates GSK3α/β activity in the cortex and hippocampus of APP/PS1 transgenic mice
- 2024
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Ingår i: Journal of Integrative Neuroscience. - : IMR press. - 0219-6352 .- 1757-448X. ; 23:7
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Physical exercise has been shown to be beneficial for individuals with Alzheimer's disease (AD), although the underlying mechanisms are not fully understood.METHODS: Six-month-old Amyloid precursor protein/Presenilin 1 (APP/PS1) transgenic (Tg) mice and wild-type (Wt) mice were randomly assigned to either a sedentary group (Tg-Sed, Wt-Sed) or an exercise group (Tg-Ex, Wt-Ex) undertaking a 12-week, moderate-intensity treadmill running program. Consequently, all mice were tested for memory function and amyloid β (Aβ) levels and phosphorylation of tau and protein kinase B (Akt)/glycogen synthase kinase-3 (GSK3) were examined in tissues of both the cortex and hippocampus.RESULTS: Tg-Sed mice had severely impaired memory, higher levels of Aβ, and increased phosphorylation of tau, GSK3α tyrosine279, and GSK3β tyrosine216, but less phosphorylation of GSK3α serine21, GSK3β serine9, and Akt serine473 in both tissues than Wt-Sed mice in respective tissues. Tg-Ex mice showed significant improvement in memory function along with lower levels of Aβ and less phosphorylation of tau (both tissues), GSK3α tyrosine279 (both tissues), and GSK3β tyrosine216 (hippocampus only), but increased phosphorylation of GSK3α serine21 (both tissues), GSK3β serine9 (hippocampus only), and Akt serine473 (both tissues) compared with Tg-Sed mice in respective tissues.CONCLUSIONS: Moderate-intensity aerobic exercise is highly effective in improving memory function in 9-month-old APP/PS1 mice, most likely through differential modulation of GSK3α/β phosphorylation in the cortex and hippocampus.
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| 7. |
- Khayyer, Zahra, et al.
(författare)
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Transcranial direct current stimulation based on qEEG combining positive psychotherapy for major depression
- 2018
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Ingår i: Journal of Integrative Neuroscience. - 0219-6352 .- 1757-448X. ; 17:2, s. 89-96
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Tidskriftsartikel (refereegranskat)abstract
- Frontal cortex activity in the left hemisphere during depression is reduced. Transcranial direct current stimulation (tDCS) is a non-invasive neuromodulation technique that can increase frontal cortex activity. Therapy based on tDCS and positive psychology (PP) therapy was applied improving patients' quality of life. The present study compared three conditions participants with clinical depression; (a) tDCS therapy, (b) positive psychotherapy, and (c) combined treatment. Hamilton Depression Rating Scale (HDRS), Adult State Hope Scale and Optimism/Pessimism Scale (OPS) was used at baseline, 2 weeks, 4-weeks and 3-months follow-up. Combined condition participants showed greater reduction in depressed mood, improved hope and optimism after 4-weeks as well as during 3-months follow-up than the other conditions. The results are discussed in terms of additive or synergistic relation between tDCS and PP treatment. Future studies should (a) use larger sample-sizes, (b) include no-treatment control conditions, (c) include double-blind designs, (d) control for previous or on-going drug therapy, (d) control for previous or ongoing psychotherapy. Furthermore, future studies should aim to increase theoretical understanding by investigating whether the relation between tDCS and psychotherapy are additive or synergistic.
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| 8. |
- Khayyer, Zahra, et al.
(författare)
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Transcranial direct current stimulation based on quantitative electroencephalogram combining positive psychotherapy for major depression
- 2018
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Ingår i: Journal of Integrative Neuroscience. - 0219-6352. ; 17:2, s. 141-155
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Tidskriftsartikel (refereegranskat)abstract
- Frontal cortex activity in the left hemisphere during depression is reduced. Transcranial direct current stimulation (tDCS) is a non-invasive neuromodulation technique that can increase frontal cortex activity. Therapy based on tDCS and positive psychology (PP) therapy was applied improving patients’ quality of life. The present study compared three conditions participants with clinical depression; (a) tDCS therapy, (b) positive psychotherapy, and (c) combined treatment. Hamilton Depression Rating Scale (HDRS), Adult State Hope Scale and Optimism/Pessimism Scale (OPS) was used at baseline, 2 weeks, 4-weeks and 3-months follow-up. Combined condition participants showed greater reduction in depressed mood, improved hope and optimism after 4-weeks as well as during 3-months follow-up than the other conditions. The results are discussed in terms of additive or synergistic relation between tDCS and PP treatment. Future studies should (a) use larger sample-sizes, (b) include no-treatment control conditions, (c) include double-blind designs, (d) control for previous or on-going drug therapy, (d) control for previous or ongoing psychotherapy. Furthermore, future studies should aim to increase theoretical understanding by investigating whether the relation between tDCS and psychotherapy are additive or synergistic.
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| 9. |
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| 10. |
- Magnusson, Beatrice M., et al.
(författare)
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Symptoms and disability after mild traumatic brain injury : a five-year follow-up
- 2024
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Ingår i: Journal of Integrative Neuroscience. - : IMR Press. - 0219-6352 .- 1757-448X. ; 23:2
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Every year, many people suffer from traumatic brain injuries (TBI) with dramatic consequences for both the victim and their close relatives in the form of remaining lifelong symptoms and functional disabilities as a result.METHODS: This study evaluates the outcomes of 49 patients after mild TBI (mTBI) at follow-up after 5 years by using the Rivermead Post-Concussion Symptoms Questionnaire (RPQ) to assess post-TBI symptoms and the Glasgow Outcome Scale Extended (GOSE) to assess disability. The specific aim was to evaluate post-TBI characteristics concerning age, gender, pre-injury systemic disease, computed tomography (CT) result and additional TBIs.RESULTS: Almost eighty percent reported RPQ symptoms, the most common for both genders being fatigue (51%) and poor concentration (51%). Seventy-six percent had a good recovery, 18% moderate disability, while 6% reported severe disability. The number of symptoms was significantly correlated to the level of disability. All participants with severe disability had repeated mTBI. Only twenty-one percent reported that they received some form of rehabilitation intervention after their mTBI.CONCLUSIONS: Five years after suffering mTBI, patients reported high rates of symptoms and disabilities. Our findings suggest that tailored rehabilitation interventions should be designed to identify mTBI patients in need of early rehabilitation. This would result in minimized suffering for the individual and improved cost-effectiveness for society.
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