Volumetric and functional connectivity changes of the thalamic nuclei in different stages of Alzheimer's disease.

OBJECTIVE: Memory processes known to be impaired in Alzheimer's disease (AD) are maintained by a large-scale neurocognitive network with subcortical components, including the thalamus. Therefore, we aimed to examine the volumetric and functional changes of the thalamic nuclei at different scales across AD stages. METHODS: MRI data of patients diagnosed with 20 AD dementia (ADD), 30 amnestic mild cognitive impairment (MCI), and 30 subjective cognitive impairment (SCI) were used. Volumetric and functional connectivity analyzes were performed by dividing the thalamus into anterior, medial, posterior, lateral and intralaminar nucleus groups and their specific subnuclei. RESULTS: In the course of AD, the volume of the medial group nuclei, especially the mediodorsal medial magnocellular (MDm) nucleus, decreases. Medial group nuclei and MDm functional connectivity with frontal areas were decreased both in ADD and MCI compared to SCI group, while both of them increased their functional connectivity with visual areas in the ADD group compared to the MCI group. CONCLUSIONS: Our study suggests that the medial group of the thalamus, and specifically the MDm, may be affected in AD. SIGNIFICANCE: Specific thalamic nuclei may be a critical anatomical region for investigating structural and functional changes in AD.

Hyperconnecitivity between dorsal attention and frontoparietal networks predicts treatment response in obsessive-compulsive disorder.

Obsessive-compulsive disorder (OCD) presented with repetitive obsessions and/or compulsions were associated with disrupted resting-state functional connectivity (rs-FC). To investigate the pharmacological treatment effect on rs-FC changes in OCD patients we conducted the seed-to-voxel FC analyses using dorsal attention network (DAN), default mode network (DMN), salience network (SN) and frontoparietal network (FPN) and basal ganglia seeds. Twenty-two healthy subjects and twenty-four unmedicated OCD patients underwent resting-state functional magnetic resonance imaging. Patients were rescanned after 12 weeks of escitalopram treatment. We found increased FC both within the DAN and between the DAN and the FPN which was ameliorated after medication and correlated significantly with the clinical improvement in obsession scores. We also observed an anticorrelation between the left caudate and the supplementary motor area in unmedicated OCD patients which also normalized with treatment. Results further showed treatment related normalization of orbitofrontal cortex hyperconnectivity with DMN and hypoconnectivity with DAN whereas aberrant FC between the SN and visual areas appears to be a medication effect. We suggest that DAN to FPN hyperconnectivity which is positively correlated with clinical improvement in obsession scores at pre-treatment stage in present study has a potential for being a neuroimaging marker to predict the treatment response in OCD.

Functional and structural connectivity in the Papez circuit in different stages of Alzheimer's disease.

OBJECTIVE: Alzheimer's disease (AD) is a progressive neurodegenerative continuum with memory impairment. We aimed to examine the detailed functional (FC) and structural connectivity (SC) pattern of the Papez circuit, known as the memory circuit, along the AD. METHODS: MRI data of 15 patients diagnosed with AD dementia (ADD), 15 patients with the amnestic mild cognitive impairment (MCI), and 15 patients with subjective cognitive impairment were analyzed. The FC analyses were performed between main nodes of the Papez circuit, and the SC was quantified as fractional anisotropy (FA) of the main white matter pathways of the Papez circuit. RESULTS: The FC between the retrosplenial (RSC) and parahippocampal cortices (PHC) was the earliest affected FC, while a manifest SC change in the ventral cingulum and fornix was observed in the later ADD stage. The RSC-PHC FC and the ventral cingulum FA efficiently predicted the memory performance of the non-demented participants. CONCLUSIONS: Our findings revealed the importance of the Papez circuit as target regions along the AD. SIGNIFICANCE: The ventral cingulum connecting the RSC and PHC, a critical overlap area between the Papez circuit and the default mode network, seems to be a target region associated with the earliest objective memory findings in AD.

Morphometric analysis of medial temporal lobe subregions in Alzheimer's disease using high-resolution MRI.

The spread pattern of progressive degeneration seen in Alzheimer's disease (AD) to small-scale medial temporal lobe subregions is critical for early diagnosis. In this context, it was aimed to examine the morphometric changes of the hippocampal subfields, amygdala nuclei, entorhinal cortex (ERC), and parahippocampal cortex (PHC) using MRI. MRI data of patients diagnosed with 20 Alzheimer's disease dementia (ADD), 30 amnestic mild cognitive impairment (aMCI), and 30 subjective cognitive impairment (SCI) without demographic differences were used. Segmentation and parcellation were performed using FreeSurfer. The segmentation process obtained volume values of 12 hippocampal subfields and 9 amygdala nuclei. Thickness values of ERC and PHC were calculated with the parcellation process. ANCOVA was performed using age, education and gender as covariates to evaluate the intergroup differences. Linear discriminant analysis was used to investigate whether atrophy predicted groups at an early stage. ERC and PHC thickness decreased significantly throughout the disease continuum, while only ERC was affected in the early stage. When the hippocampal and amygdala subfields were compared volumetrically, significant differences were found in the amygdala between the SCI and aMCI groups. In the early period, only volume reduction in the anterior amygdaloid area of the amygdala nuclei exceeded the significance threshold. Research on AD primarily focuses on original hippocampocentric structures and their main function which is episodic memory. Our results emphasized the significance of so far relatively neglected olfactocentric structures and their functions, such as smell and social cognition in the pre-dementia stages of the AD process.

Altered learning and transfer abilities in Korsakoff's syndrome depending on task complexity.

Korsakoff's syndrome (KS) is characterized by episodic memory impairment due to damage to the medial diencephalic structures. Although commonly associated with chronic alcoholism, starvation due to the hunger strike is one of its nonalcoholic causes. Learning the stimulus-response associations and transferring the just-learned associations to novel combinations were previously tested by specific tasks in memory-impaired patients with hippocampal, basal forebrain, and basal ganglia damage. To add to this previous research, we aimed to use the same tasks in a group of patients with hunger strike-related KS presenting a stable isolated amnestic profile. Twelve patients with hunger strike-related KS and matched healthy controls were tested in two tasks varying in task complexity. Each task included two phases: the initial phase is feedback-based learning of (simple vs. complex) stimulus-response associations, and the following phase is transfer generalization (in the presence vs. absence of feedback). On a task involving simple associations, five patients with KS failed to learn the associations, while the other seven patients showed intact learning and transfer. On the other task involving more complex associations, seven patients showed slower learning and failed at transfer generalization, whereas the other five patients failed even at the acquisition phase. These findings of a task-complexity-related impairment on associative learning and transfer represent a distinct pattern from the spared learning but impaired transfer previously observed on these tasks in patients with medial temporal lobe amnesia.

Evaluation of Resting-State Functional Magnetic Resonance Imaging Findings of Patients with Social Anxiety Disorder. / Sosyal Anksiyete Bozuklugu Olan Hastalarda Dinlenim Durumu Islevsel Manyetik Rezonans Görüntüleme Bulgularinin Incelenmesi.

OBJECTIVE: The most prominent functional magnetic resonance imaging findings about social anxiety disorder are increased activity in emotional regulation areas (amygdala, insula, hippocampus, dorsal anterior cingulate cortex) and fear circuit, and altered activity in prefrontal cortex. This study aims to investigate network abnormalities during resting state. METHOD: Resting state functional magnetic resonance images of 21 drug-free patients with social anxiety disorder and 21 healthy controls (matched on age, gender, and years of education) were recorded. Resting state functional connectivity networks were obtained with independent component analysis, and were compared by using the voxel based t-test between the two groups. RESULTS: Patients with social anxiety disorder displayed decreased intrinsic functional connectivity in the anterior component of the salience network (left orbitofrontal cortex) and increased intrinsic functional connectivity in the posterior component of the salience network (left supramarginal gyrus). CONCLUSION: Most of the studies about social anxiety disorder mainly focused on fear circuit and emotional regulation areas by using anxiety provoking tasks or by using seed based analysis of functional connectivity. By applying a whole-brain independent component analysis, we found altered functional connectivity in the salience network, but no significant difference was found in the fear circuit areas. Our results suggest that abnormal connectivity in the salience network might play a crucial role in the neurobiology of social anxiety disorder.

Altered Resting State Functional Connectivity and Its Correlation with Cognitive Functions at Ultra High Risk for Psychosis.

The aim of this study is to identify robust resting state-functional connectivity (rs-FC) alterations and their correlations with the neuropsychological characteristics of Ultra-High Risk (UHR) for psychosis subjects compared to healthy controls (HCs). Twenty individuals with UHR and sixteen HCs underwent resting-state functional magnetic resonance imaging (rs-fMRI) and a cognitive battery evaluating attention, episodic memory and executive functions. Compared to HCs, UHR individuals showed working memory and set-shifting impairments. In functional connectivity (FC) analyses, the Default Mode Network (DMN) of the UHR subjects displayed increased FC with the visual areas and decreased FC with the Dorsal Attention Network (DAN). Additionally, the salience network (SN) of the UHR subjects displayed increased connectivity with wide posterior cortical areas in the temporal, parietal and occipital lobes, corresponding to posterior nodes of the SN itself, the Somato-Motor Network (SMN) and the DAN. The SN connectivity with the left SMN and DAN was positively correlated with the Trail Making Test - B scores of the UHR subjects. These findings show that the SN and DMN, which mostly show abnormal connectivity patterns in psychosis, are also affected in UHR subjects, while the SN plays a more central role with its hyperconnectivity to the DAN and SMN.

Default mode and dorsal attention network involvement in visually guided motor sequence learning.

Motor sequence learning (MSL) paradigms are often used to investigate the neural processes underlying the acquisition of complex motor skills. Behavioral and neuroimaging studies have indicated an early stage in which spatial learning is prominent and a late stage of automatized performance after multiple training periods. Functional magnetic resonance imaging (fMRI) studies yielded both decreased and increased activations of the sensorimotor and association areas. However, task-negative and task-positive intrinsic connectivity networks (ICNs), the default mode (DMN) and dorsal attention (DAN) networks involved in governing attention demands during various task conditions were not specifically addressed in most studies. In the present fMRI study, a visually guided MSL (VMSL) task was used for bringing roles of visuospatial and motor attention into foreground in order to investigate the role of attention-related ICNs in MSL. Seventeen healthy, right-handed participants completed training and test sessions of VMSL during fMRI on the 1st day. Then, after daily training for three consecutive days outside the scanner, they were re-tested during the 5th day's scanning session. When test session after early learning period was compared with training session, activation decrease was observed in the occipito-temporal fusiform cortex, while task-related suppression of DMN was reduced. Reduced deactivation after early learning was correlated with decreased error rates. After late learning stage we observed activation decreases in bilateral superior parietal lobules of task-positive DAN, dorsal precunei, and cerebellum. Reduced activity in left posterior parietal and right cerebellar regions were correlated with gains in speed, error rate, respectively. This dissociation in activity changes of DMN and DAN related areas suggests that DAN shows high contribution during both early and late MSL stages, possibly due to attention requirement for automatization of spatial and temporal aspects of motor sequence. In contrast, spatial learning occurring during early MSL stage was sufficient for releasing DMN resources.

Examination of self-care agency and quality of life in individuals with chronic venous disease.

AIM: This study aims to investigate self-care agency and quality of life (QoL) in persons with chronic venous disease of the lower extremities. METHODS: This descriptive study was carried out between December 2014 and September 2016. The study population consisted of patients admitted to Erzurum Regional Training and Research Hospital Clinic of Surgical Cardiovascular Diseases and who had been diagnosed with lower extremity venous disease. The study sample comprised 312 patients who meet the inclusion criteria among this population admitted at the said dates. For data collection, the Patient Information Form, Self-Care Agency Scale, and Venous Insufficiency Epidemiological and Economic Study - Quality of Life/Symptoms Scale (VEINES-QOL/SYM) were used. The data were evaluated using percentage distribution, means, analysis of variance, post-hoc test, t-test, Mann-Whitney U-test and Kruskal-Wallis test. RESULTS: The mean Self-Care Agency Scale score of the patients with lower extremity venous disease was 102.33±18.20, and their mean VEINES-QOL/Sym score was 74.95±12.86, indicating a moderate level. CONCLUSION: As a result, this study found the factors that significantly affected mean Self-Care Agency scores and mean QoL scores of the patients in terms of their level of education, employment status, BMI, smoking habits, and conditions about chronic diseases. Positive correlation was found between mean Self-Care Agency scores and QoL scores of the patients.

Functional connectivity disturbances of ascending reticular activating system and posterior thalamus in juvenile myoclonic epilepsy in relation with photosensitivity: A resting-state fMRI study.

OBJECTIVE: Juvenile myoclonic epilepsy (JME) is typified by the occurrence of myoclonic seizures after awakening, though another common trait is myoclonic seizures triggered by photic stimulation. We aimed to investigate the functional connectivity (FC) of nuclei in the ascending reticular activating system (ARAS), thalamus and visual cortex in JME with and without photosensitivity. METHODS: We examined 29 patients with JME (16 photosensitive (PS), 13 non- photosensitive-(NPS)) and 28 healthy controls (HCs) using resting-state functional magnetic resonance imaging (rs-fMRI). Seed-to-voxel FC analyses were performed using 25 seeds, including the thalamus, visual cortex, and ARAS nuclei. RESULTS: Mesencephalic reticular formation seed revealed significant hyperconnectivity between the bilateral paracingulate gyrus and anterior cingulate cortex in JME group, and in both JME-PS and JME-NPS subgroups compared to HCs (pFWE-corr < 0.001; pFWE-corr < 0.001; pFWE-corr = 0.002, respectively). Locus coeruleus seed displayed significant hyperconnectivity with the bilateral lingual gyri, intracalcarine cortices, occipital poles and left occipital fusiform gyrus in JME-PS group compared to HCs (pFWE-corr <0.001). Additionally, locus coeruleus seed showed significant hyperconnectivity in JME-PS group compared to JME-NPS group with a cluster corresponding to the bilateral lingual gyri and right intracalcarine cortex (pFWE-corr < 0.001). Lastly, the right posterior nuclei of thalamus revealed significant hyperconnectivity with the right superior lateral occipital cortex in JME-PS group compared to HCs (pFWE-corr < 0.002). CONCLUSIONS: In JME, altered functional connectivity of the arousal networks might contribute to the understanding of myoclonia after awakening, whereas increased connectivity of posterior thalamus might explain photosensitivity.

B-Tensor: Brain Connectome Tensor Factorization for Alzheimer's Disease.

AD is the highly severe part of the dementia spectrum and impairs cognitive abilities of individuals, bringing economic, societal and psychological burdens beyond the diseased. A promising approach in AD research is the analysis of structural and functional brain connectomes, i.e., sNETs and fNETs, respectively. We propose to use tensor representation (B-tensor) of uni-modal and multi-modal brain connectomes to define a low-dimensional space via tensor factorization. We show on a cohort of 47 subjects, spanning the spectrum of dementia, that diagnosis with an accuracy of 77% to 100% is achievable in a 5D connectome space using different structural and functional connectome constructions in a uni-modal and multi-modal fashion. We further show that multi-modal tensor factorization improves the results suggesting complementary information in structure and function. A neurological assessment of the connectivity patterns identified largely agrees with prior knowledge, yet also suggests new associations that may play a role in the disease progress.

Functional connectivity analysis of patients with temporal lobe epilepsy displaying different ictal propagation patterns.

The pathophysiology of switch-of lateralization and bilateral temporal asynchrony, which are scalp EEG ictal propagation patterns (iPP) in temporal lobe epilepsy (TLE), is poorly understood. We aimed to analyse functional connectivity (FC) of the temporal lobe and related areas in patients with TLE with iPP (iPP-TLE) and without iPP (non-iPP TLE). Twelve patients with iPP-TLE, 13 patients with non-iPP TLE, and 13 healthy controls (HC) underwent resting-state functional MRI (fMRI). Seed-based FC was analysed between the homologous insulae, hippocampi, amygdalae, parahippocampal, superior temporal, and middle temporal gyri. FC was reduced between homologous temporal lobe areas in patients with TLE compared with HCs. Patients with non-iPP TLE displayed decreased FC between the homologous parahippocampal and superior temporal gyri, and patients with iPP-TLE had lower FC between the homologous insulae, parahippocampal and superior temporal gyri compared with HC. Furthermore, patients with iPP-TLE tended to have lower FC between the bilateral insulae when compared with patients with non-iPP TLE. Reduced FC of interhemispheric connections between temporal lobes and related areas might be an adaptive change to protect contralateral areas in seizure propagation. The insula showed decreased FC between two hemispheres in patients with iPP-TLE, assuming a role in ictal scalp propagation pattern changes in TLE.

Functional neural substrates of football fanaticism: Different pattern of brain responses and connectivity in fanatics.

AIM: Sports activities provide social interaction for humans. Commitment to a given team is a salient feature of being a sports fan and becomes a prominent part of self-identification for fanatics. Emotion, subjective hedonic experience, and non-romantic love are related to fan behaviors. Few studies have evaluated the neural basis of sports fanaticism. METHODS: Thirty men, including 16 football fanatics and 14 non-fanatics, with a mean age of 27.4 ± 6.4 years (range, 20-48 years) were enrolled. Subjects underwent functional MRI while watching a set of goals scored by favorite, rival, and neutral teams. RESULTS: The analysis of variance in a general linear model revealed a significant Group × Condition interaction effect in the bilateral dorsal anterior cingulate cortex (dACC) that was more prominent in the left hemisphere. In the post-hoc comparisons, fanatics showed increased activation in bilateral dACC, supplementary motor area, superior frontal cortex, right dorsolateral prefrontal cortex, and right insula for Favorite > Neutral contrast and an increased activation in bilateral dACC and supplementary motor area for Rival > Neutral contrast. Seed-based connectivity analyses using the areas with significant activation differences revealed increased connectivity between dACC and several regions, including the left posterior lateral temporal area, insula, bilateral medial temporal area, and medial superior frontal area as well as the basal ganglia in fanatics compared to non-fanatics. CONCLUSION: Our results suggest that football fanatics exhibit a different brain activation and connectivity pattern from non-fanatics, both under favorable and unfavorable conditions. This brain activity and connectivity pattern under emotionally laden conditions may represent higher responses to rewards, higher emotional valence attribution, and stronger motivational state of football fanatics, which might underlie their unusual behavioral responses.

White-matter changes in early and late stages of mild cognitive impairment.

Mild Cognitive Impairment (MCI) is characterized by cognitive deficits that exceed age-related decline, but not interfering with daily living activities. Amnestic type of the disorder (aMCI) is known to have a high risk to progress to Alzheimer's Disease (AD), the most common type of dementia. Identification of very early structural changes in the brain related to the cognitive decline in MCI patients would further contribute to the understanding of the dementias. In the current study, we target to investigate whether the white-matter changes are related to structural changes, as well as the cognitive performance of MCI patients. Forty-nine MCI patients were classified as Early MCI (E-MCI, n = 24) and Late MCI (L-MCI, n = 25) due to their performance on The Free and Cued Selective Reminding Test (FCSRT). Age-Related White-Matter Changes (ARWMC) scale was used to evaluate the white-matter changes in the brain. Volumes of specific brain regions were calculated with the FreeSurfer program. Both group and correlation analyses were conducted to show if there was any association between white-matter hyperintensities (WMHs) and structural changes and cognitive performance. Our results indicate that, L-MCI patients had significantly more WMHs not in all but only in the frontal regions compared to E-MCI patients. Besides, ARWMC scores were not correlated with total hippocampal and white-matter volumes. It can be concluded that WMHs play an important role in MCI and cognitive functions are affected by white-matter changes of MCI patients, especially in the frontal regions.

Implicit contextual learning in spinocerebellar ataxia.

OBJECTIVE: Cerebellum is traditionally associated with motor functions, but recently its functions were broadened to include cognitive and affective functions as well. The impairment of these nonmotor functions was subsumed under the term cerebellar cognitive-affective syndrome (CCAS). Spinocerebellar ataxias (SCAs) are a family of hereditary degeneration, which is associated with progressive atrophy of the cerebellum. This study aimed to examine the cerebellar contribution to nonmotor implicit learning, which is the ability to acquire visual contextual information via repeated spatial configurations from the environment without conscious awareness in patients with SCA. METHOD: Twenty patients with SCA and matched healthy controls performed implicit contextual learning task that is a nonmotor, implicit, visual learning task consisting displays of a target (letter T) and a number of distractors (letter L). RESULTS: We found implicit contextual learning impairment vis-à-vis spared visuomotor skill learning in SCA. Moreover, this impairment did not correlate with any other measure, including demographics, clinical measures, and neuropsychological measures. CONCLUSION: These findings broaden the role of cerebellum in nonmotor, implicit, spatial learning processes. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Intrinsic functional connectivity in social anxiety disorder with and without comorbid attention deficit hyperactivity disorder.

Neuroimaging research about social anxiety disorder (SAD) points to hyperactivity in the fear circuit and altered connectivity between the fear circuit and the intrinsic connectivity networks that modulate it. We investigated intrinsic functional connectivity changes in SAD patients by taking into consideration the commonly overlooked comorbidity of attention deficit hyperactivity disorder (ADHD). We compared intrinsic functional connectivity alterations in 16 patients with pure SAD, 18 patients with SAD and comorbid ADHD and 21 healthy controls using seed-to-voxel functional connectivity analyses. Hypoconnectivity of the right fusiform gyrus with the left lingual gyrus was the unique difference between whole SAD group and healthy controls, while in the pure SAD group the fusiform gyrus displayed hypoconnectivity with the posterior default mode network (DMN) regions. In contrast, ADHD comorbidity was associated with hyperconnectivities of the salience network (SN) with the fusiform cortex and the posterior DMN regions, and hyperconnectivities of the posterior DMN with visual, somatosensory and motor cortices. The dichotomic dissociation of the SAD related functional connectivity changes into hypoconnectivities in the pure SAD group vs hyperconnectivities in the SAD-ADHD group leads also to the question, whether ADHD treatment can be considered an alternative for selected SAD cases.

Familial Mediterranean fever patients homozygous for E148Q variant may have milder disease.

AIM: Familial Mediterranean fever (FMF) results from MEFV gene mutations. E148Q is a variant of unknown significance in MEFV. We aimed to define characteristics of FMF patients homozygous for E148Q, check for other MEFV variants in a subgroup, and compare the characteristics with FMF patients carrying other mutations. METHODS: Thirty FMF patients homozygous for E148Q were reviewed. MEFV variant analysis was performed with strip assay. All MEFV exons were screened by direct DNA sequencing in 14 randomly selected E148Q/E148Q patients. E148Q was also checked in 100 healthy adolescents. We compared the characteristics of FMF patients between three groups: E148Q/E148Q (n = 30), M694V/E148Q (n = 19) and exon 10/exon 10 MEFV mutations (n = 48). RESULTS: Among 30 FMF patients (E148Q/E148Q), the median age at disease onset and diagnosis were 60 (12-168) and 94 (41-196) months, respectively. Fifteen (50%) patients had mild, 14 (46.7%) moderate and one (3.3%) had severe disease. Twenty-two (73.3%) patients had complete, seven (23.3%) had incomplete response to colchicine, while only one was unresponsive. The detected MEFV variants in 14 E148Q/E148Q FMF patients were as follows: R314R (n = 9; 64.3%), E474E (n = 13; 92.9%), Q476Q (n = 13; 92.9%), D510D (n = 13; 92.9%), and P588P (n = 8; 57.1%). The E148Q allele frequency was 6.5% in healthy adolescents. When compared to FMF patients with other MEFV mutations, disease onset was later, disease was less severe and the ratio of patients responding completely to colchicine was higher in E148Q/E148Q patients. CONCLUSION: Patients homozygous for E148Q and negative for other pathogenic MEFV variants may display FMF phenotype and may experience moderate/severe disease activity, although the disease may be milder when compared to FMF patients with other mutations.

A combined VBM and DTI study of schizophrenia: bilateral decreased insula volume and cerebral white matter disintegrity corresponding to subinsular white matter projections unlinked to clinical symptomatology.

PURPOSE: Grey matter and white matter changes within the brain are well defined in schizophrenia. However, most studies focused on either grey matter changes or white matter integrity separately; only in limited number of studies these changes were interpreted in the same frame. In addition, the relationship of these findings with clinical variables is not clearly established. Here, we aimed to investigate the grey matter and white matter changes in schizophrenia patients and exhibit the relation of these imaging findings with clinical variables. METHODS: A total of 20 schizophrenia patients and 16 matched healthy controls underwent magnetic resonance imaging to investigate the grey matter and white matter alterations that occur in schizophrenia patients using voxel-based morphometry (VBM) and whole brain voxel-wise analysis of diffusion tensor imaging (DTI) parameters with SPM8, respectively. While the preprocessing steps of VBM were performed with the default parameters of VBM8 toolbox, the preprocessing steps of DTI were carried out using FSL. Additionally, VBM results were correlated with clinical variables. RESULTS: Bilateral insula showed decreased grey matter volume in schizophrenia patients compared with healthy controls (P < 0.01). The opposite contrast did not show a significant difference. Psychiatric scores, duration of illness, and age were not correlated with the decreased grey matter volume of insula in schizophrenia patients. DTI analysis revealed a significant increase in mean, radial, and axial diffusivity, mainly of the fibers of bilateral anterior thalamic radiation and superior longitudinal fasciculus with left predominance, which intersected with bilateral subinsular white matter (P < 0.05). CONCLUSION: Our findings suggest that insula may be the main affected brain region in schizophrenia, which is also well supported by the literature. Our results were independent of disease duration and schizophrenia symptoms. White matter alterations were observed within bilateral anterior thalamic radiation and superior longitudinal fasciculus that intersects with subinsular white matter. Studies with larger sample sizes and more detailed clinical assessments are required to understand the function of insula in the neurobiology of schizophrenia.

Evidence for alterations of the right inferior and superior longitudinal fasciculi in patients with social anxiety disorder.

The aim of our study was to detect white matter (WM) regions being involved in the pathophysiology of SAD. We applied diffusion tensor imaging in 22 consecutive adult patients (11 women and 11 men) with SAD and 22 age and sex-matched healthy control subjects. We examined white matter (WM) alterations between the patients with social anxiety disorder (SAD) and healthy controls by a whole-brain analysis. We found that fractional anisotropy (FA) was reduced in patients with SAD compared with controls in the temporal part of right inferior longitudinal fasciculus (ILF) and the occipito-temporal part of the right superior longitudinal fasciculus (SLF). We also identified that in these regions FA was negatively correlated with the severity of anxiety. Our results suggest that the lateral temporal and occipito-temporal WM microstructure plays a role in mediating social interactions, and a pattern of WM abnormality in the right ILF and SLF may be implicated in the pathophysiology of SAD plausibly through leading to deficits in face processing mechanisms.

Physiological responses of the M1 sainfoin (Onobrychis viciifolia Scop) plants to gamma radiation.

Effects of gamma radiation on physiological responses of the M1 sainfoin plants were investigated. Seeds of sainfoin ecotype 'Koças' were exposed to 0, 400, 500 and 600Gy from a 60Co source at a dose rate of 0.483 kGyh-1. Irradiated and unirradiated seeds were sown into culture vessels containing MS-basal medium to be cultured for 30 days under in vitro conditions. At the end of this period, seedlings, which germinated from the radiated and unirradiated seeds, were transferred into pots in a growth chamber for 30 days more. Chlorophyll contents, activities of superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX) and glutathione reductase (GR), as well as contents of monodehydroascorbate reductase (MDA) and proline were examined in unirradiated and irradiated 60-day-old seedlings. Overall, the activities of the antioxidant enzymes (SOD, CAT and GR) and contents of chlorophyll and proline in the leaves tended to increase after irradiation in a dose-dependent manner. By contrast, the activity of APX decreased. The lipid peroxidation characterized by the MDA content remained unchanged, except after irradiation to 500Gy. The highest CAT activity and the highest proline content were observed after irradiation to the highest dose of 600Gy. The highest SOD and GR activities were observed after irradiation to the lowest tested dose of 400Gy. This is the first study that provided basic information on the impact of gamma radiation on physiological responses of sainfoin and its radiosensitivity. These findings will be useful in development of a mutation breeding program of sainfoin.