The Experts below are selected from a list of 1299 Experts worldwide ranked by ideXlab platform
Johan N. Lundström - One of the best experts on this subject based on the ideXlab platform.
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Morphological changes in secondary, but not primary, sensory cortex in individuals with life-long olfactory sensory deprivation.
NeuroImage, 2020Co-Authors: Moa G. Peter, Gustav Mårtensson, Elbrich M. Postma, Love Engström Nordin, Eric Westman, Sanne Boesveldt, Johan N. LundströmAbstract:Individuals with congenital sensory deprivation usually demonstrate altered brain morphology in areas associated with early processing of the absent sense. Here, we aimed to establish whether this also applies to individuals born without a sense of smell (congenital anosmia) by comparing cerebral morphology between 33 individuals with isolated congenital anosmia and matched controls. We detected no morphological alterations in the primary olfactory (piriform) cortex. However, individuals with anosmia demonstrated gray matter volume atrophy in bilateral olfactory sulci, explained by decreased cortical area, curvature, and sulcus depth. They further demonstrated increased gray matter volume and cortical thickness in the medial Orbital Gyri; regions closely associated with olfactory processing, sensory integration, and value-coding. Our results suggest that a lifelong absence of sensory input does not necessarily lead to morphological alterations in primary sensory cortex and extend previous findings with divergent morphological alterations in bilateral orbitofrontal cortex, indicating influences of different developmental processes.
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Structural changes in secondary, but not primary, sensory cortex in individuals with congenital olfactory sensory loss
2019Co-Authors: Moa G. Peter, Gustav Mårtensson, Elbrich M. Postma, Love Engström Nordin, Eric Westman, Sanne Boesveldt, Johan N. LundströmAbstract:Individuals with congenital sensory loss usually demonstrate altered brain morphology in areas associated with early processing of the lost sense. Here, we aimed to establish whether this also applies to individuals born without a sense of smell (congenital anosmia) by comparing cortical morphology between 33 individuals with isolated congenital anosmia and matched controls. We detected no structural alterations in the primary olfactory (piriform) cortex. However, individuals with anosmia demonstrated gray matter volume atrophy in bilateral olfactory sulci, explained by decreased cortical area, curvature, and sulcus depth. They further demonstrated increased gray matter volume and cortical thickness in the medial Orbital Gyri; regions closely associated with olfactory processing, sensory integration, and value-coding. Our results suggest that a lifelong absence of sensory input does not necessarily lead to morphological alterations in primary sensory cortex and extend previous findings with divergent morphological alterations in bilateral orbitofrontal cortex, indicating influences of different plastic processes.
Cathy J Price - One of the best experts on this subject based on the ideXlab platform.
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a pet study of stimulus and task induced semantic processing
NeuroImage, 2002Co-Authors: Uta Noppeney, Cathy J PriceAbstract:To investigate the neural correlates of semantic processing, previous functional imaging studies have used semantic decision and generation tasks. However, in addition to activating semantic associations these tasks also involve executive functions that are not specific to semantics. The study reported in this paper aims to dissociate brain activity due to stimulus-driven semantic associations and task-induced semantic and executive processing by using repetition and semantic decision on auditorily presented words in a cognitive conjunction design. The left posterior inferior temporal, inferior frontal (BA 44/45), and medial Orbital Gyri were activated by both tasks, suggesting a general role in stimulus-driven semantic and phonological processing. In addition, semantic decision increased activation in (i) left ventral inferior frontal cortex (BA 47), right cerebellum, and paracingulate, which have all previously been implicated in executive functions, and (ii) a ventral region in the left anterior temporal pole which is commonly affected in patients with semantic impairments. We attribute activation in this area to the effortful linkage of semantic features. Thus, our study replicated the functional dissociation between dorsal and ventral regions of the left inferior frontal cortex. Moreover, it also dissociated the semantic functions of the left posterior inferior temporal gyrus and anterior temporal pole: The posterior region subserves stimulus-driven activation of semantic associations and the left anterior region is involved in task-induced association of semantic information.
Seung Bong Hong - One of the best experts on this subject based on the ideXlab platform.
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white matter alterations in narcolepsy patients with cataplexy tract based spatial statistics
Journal of Sleep Research, 2016Co-Authors: Yun K Park, Ohhun Kwon, Seung Bong HongAbstract:Summary Functional imaging studies and voxel-based morphometry analysis of brain magnetic resonance imaging showed abnormalities in the hypothalamus–thalamus–orbitofrontal pathway, demonstrating altered hypocretin pathway in narcolepsy. Those distinct morphometric changes account for problems in wake–sleep control, attention and memory. It also raised the necessity to evaluate white matter changes. To investigate brain white matter alterations in drug-naive narcolepsy patients with cataplexy and to explore relationships between white matter changes and patient clinical characteristics, drug-naive narcolepsy patients with cataplexy (n = 22) and healthy age- and gender-matched controls (n = 26) were studied. Fractional anisotropy and mean diffusivity images were obtained from whole-brain diffusion tensor imaging, and tract-based spatial statistics were used to localize white matter abnormalities. Compared with controls, patients showed significant decreases in fractional anisotropy of white matter of the bilateral anterior cingulate, fronto-Orbital area, frontal lobe, anterior limb of the internal capsule and corpus callosum, as well as the left anterior and medial thalamus. Patients and controls showed no differences in mean diffusivity. Among patients, mean diffusivity values of white matter in the bilateral superior frontal Gyri, bilateral fronto-Orbital Gyri and right superior parietal gyrus were positively correlated with depressive mood. This tract-based spatial statistics study demonstrated that drug-naive patients with narcolepsy had reduced fractional anisotropy of white matter in multiple brain areas and significant relationship between increased mean diffusivity of white matter in frontal/cingulate and depression. It suggests the widespread disruption of white matter integrity and prevalent brain degeneration of frontal lobes according to a depressive symptom in narcolepsy.
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Structural brain abnormalities in juvenile myoclonic epilepsy patients: volumetry and voxel-based morphometry.
Korean Journal of Radiology, 2006Co-Authors: Woo Suk Tae, Seung Bong Hong, Eun Yun Joo, Sun Jung Han, Jae-wook Cho, Dae Won Seo, Jong-min Lee, In Young Kim, Hong Sik Byun, Sun I. KimAbstract:OBJECTIVE We aimed to find structural brain abnormalities in juvenile myoclonic epilepsy (JME) patients. MATERIALS AND METHODS The volumes of the cerebrum, hippocampus and frontal lobe and the area of the corpus callosum's subdivisions were all semiautomatically measured, and then optimized voxel-based morphometry (VBM) was performed in 19 JME patients and 19 age/gender matched normal controls. RESULTS The rostrum and rostral body of the corpus callosum and the left hippocampus were significantly smaller than those of the normal controls, whereas the volume of the JME's left frontal lobe was significantly larger than that of the controls. The area of the rostral body had a significant positive correlation with the age of seizure onset (r = 0.56, p = 0.012), and the volume of the right frontal lobe had a significant negative correlation with the duration of disease (r = -0.51, p = 0.025). On the VBM, the gray matter concentration of the prefrontal lobe (bilateral Gyri rectus, anterior Orbital Gyri, left anterior middle frontal gyrus and right anterior superior frontal gyrus) was decreased in the JME group (corrected p < 0.05). CONCLUSION The JME patients showed complex structural abnormalities in the corpus callosum, frontal lobe and hippocampus, and also a decreased gray matter concentration of the prefrontal region, which all suggests there is an abnormal neural network in the JME brain.
Moa G. Peter - One of the best experts on this subject based on the ideXlab platform.
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Morphological changes in secondary, but not primary, sensory cortex in individuals with life-long olfactory sensory deprivation.
NeuroImage, 2020Co-Authors: Moa G. Peter, Gustav Mårtensson, Elbrich M. Postma, Love Engström Nordin, Eric Westman, Sanne Boesveldt, Johan N. LundströmAbstract:Individuals with congenital sensory deprivation usually demonstrate altered brain morphology in areas associated with early processing of the absent sense. Here, we aimed to establish whether this also applies to individuals born without a sense of smell (congenital anosmia) by comparing cerebral morphology between 33 individuals with isolated congenital anosmia and matched controls. We detected no morphological alterations in the primary olfactory (piriform) cortex. However, individuals with anosmia demonstrated gray matter volume atrophy in bilateral olfactory sulci, explained by decreased cortical area, curvature, and sulcus depth. They further demonstrated increased gray matter volume and cortical thickness in the medial Orbital Gyri; regions closely associated with olfactory processing, sensory integration, and value-coding. Our results suggest that a lifelong absence of sensory input does not necessarily lead to morphological alterations in primary sensory cortex and extend previous findings with divergent morphological alterations in bilateral orbitofrontal cortex, indicating influences of different developmental processes.
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Structural changes in secondary, but not primary, sensory cortex in individuals with congenital olfactory sensory loss
2019Co-Authors: Moa G. Peter, Gustav Mårtensson, Elbrich M. Postma, Love Engström Nordin, Eric Westman, Sanne Boesveldt, Johan N. LundströmAbstract:Individuals with congenital sensory loss usually demonstrate altered brain morphology in areas associated with early processing of the lost sense. Here, we aimed to establish whether this also applies to individuals born without a sense of smell (congenital anosmia) by comparing cortical morphology between 33 individuals with isolated congenital anosmia and matched controls. We detected no structural alterations in the primary olfactory (piriform) cortex. However, individuals with anosmia demonstrated gray matter volume atrophy in bilateral olfactory sulci, explained by decreased cortical area, curvature, and sulcus depth. They further demonstrated increased gray matter volume and cortical thickness in the medial Orbital Gyri; regions closely associated with olfactory processing, sensory integration, and value-coding. Our results suggest that a lifelong absence of sensory input does not necessarily lead to morphological alterations in primary sensory cortex and extend previous findings with divergent morphological alterations in bilateral orbitofrontal cortex, indicating influences of different plastic processes.
Hidenori Yamasue - One of the best experts on this subject based on the ideXlab platform.
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Volume reduction and altered sulco-gyral pattern of the orbitofrontal cortex in first-episode schizophrenia
Schizophrenia Research, 2010Co-Authors: Yoichiro Takayanagi, Tsutomu Takahashi, Lina Orikabe, Naohisa Masuda, Yuriko Mozue, Kazue Nakamura, Yasuhiro Kawasaki, Masanari Itokawa, Yoko Sato, Hidenori YamasueAbstract:Abstract Background Although clinical and neuropsychological findings have implicated functional deficits of the orbitofrontal cortex (OFC) in schizophrenia, structural magnetic resonance imaging (MRI) studies of this region have yielded inconsistent findings. In addition, it remains elusive whether the OFC morphology in first-episode patients is related to their clinical features. Method MR images were acquired from 42 (24 males, 18 females) first-episode schizophrenia patients and 35 (20 males, 15 females) age-, gender-, and parental socio-economic status (SES)-matched healthy subjects. The OFC sub - regions (Orbital gyrus and straight gyrus) were measured on contiguous 1-mm-thick coronal slices. The OFC sulco-gyral pattern was also evaluated for each subject. Furthermore, the relationships between OFC morphology and clinical measures were examined. Results The volumes of the bilateral Orbital Gyri were significantly reduced in schizophrenia patients compared with healthy subjects, whereas the volumes of the straight Gyri did not show differences between the groups. Among the schizophrenia patients, the volume of the left Orbital gyrus was inversely correlated with their SES and illness duration. The OFC sulco-gyral patterns were significantly different between the patients and controls in the right hemisphere. Conclusion This study demonstrated morphologic abnormalities of the OFC in first-episode schizophrenia patients, which may have reflected neurodevelopmental aberrations and neurodegenerative changes during the first episode of the illness. Our findings also suggest that such brain structural changes are related to the social dysfunction observed in schizophrenia.
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Volume reduction and altered sulco-gyral pattern of the orbitofrontal cortex in first-episode schizophrenia.
Schizophrenia Research, 2010Co-Authors: Yoichiro Takayanagi, Tsutomu Takahashi, Lina Orikabe, Naohisa Masuda, Yuriko Mozue, Kazue Nakamura, Yasuhiro Kawasaki, Masanari Itokawa, Yoko Sato, Hidenori YamasueAbstract:Although clinical and neuropsychological findings have implicated functional deficits of the orbitofrontal cortex (OFC) in schizophrenia, structural magnetic resonance imaging (MRI) studies of this region have yielded inconsistent findings. In addition, it remains elusive whether the OFC morphology in first-episode patients is related to their clinical features. MR images were acquired from 42 (24 males, 18 females) first-episode schizophrenia patients and 35 (20 males, 15 females) age-, gender-, and parental socio-economic status (SES)-matched healthy subjects. The OFC sub-regions (Orbital gyrus and straight gyrus) were measured on contiguous 1-mm-thick coronal slices. The OFC sulco-gyral pattern was also evaluated for each subject. Furthermore, the relationships between OFC morphology and clinical measures were examined. The volumes of the bilateral Orbital Gyri were significantly reduced in schizophrenia patients compared with healthy subjects, whereas the volumes of the straight Gyri did not show differences between the groups. Among the schizophrenia patients, the volume of the left Orbital gyrus was inversely correlated with their SES and illness duration. The OFC sulco-gyral patterns were significantly different between the patients and controls in the right hemisphere. This study demonstrated morphologic abnormalities of the OFC in first-episode schizophrenia patients, which may have reflected neurodevelopmental aberrations and neurodegenerative changes during the first episode of the illness. Our findings also suggest that such brain structural changes are related to the social dysfunction observed in schizophrenia. Copyright 2010 Elsevier B.V. All rights reserved.