Detecting language network alterations in mild cognitive impairment using task-based fMRI and resting-state fMRI: A comparative study.

OBJECTIVE: The objective of this study was to investigate the functional changes associated with mild cognitive impairment (MCI) using independent component analysis (ICA) with the word generation task functional magnetic resonance imaging (fMRI) and resting-state fMRI. METHODS: In this study 17 patients with MCI and age and education-matched 17 healthy individuals as control group are investigated. All participants underwent resting-state fMRI and task-based fMRI while performing the word generation task. ICA was used to identify the appropriate independent components (ICs) and their associated networks. The Dice Coefficient method was used to determine the relevance of the ICs to the networks of interest. RESULTS: IC-14 was found relevant to language network in both resting-state and task-based fMRI, IC-4 to visual, and IC-28 to dorsal attention network (DAN) in word generation task-based fMRI by Sorento-Dice Coefficient. ICA showed increased activation in language network, which had a larger voxel size in resting-state functional MRI than word generation task-based fMRI in the bilateral lingual gyrus. Right temporo-occipital fusiform cortex, right hippocampus, and right thalamus were also activated in the task-based fMRI. Decreased activation was found in DAN and visual network MCI patients in word generation task-based fMRI. CONCLUSION: Task-based fMRI and ICA are more sophisticated and reliable tools in evaluation cognitive impairments in language processing. Our findings support the neural mechanisms of the cognitive impairments in MCI.

Fear, Perceived Threat, and Anxiety During COVID-19 Pandemic: The Mediating Role of Cognitive Control/Flexibility and Intolerance of Uncertainty. / COVID-19 Pandemisinde Korku, Algilanan Tehdit ve Kaygi: Bilissel Kontrol/Esneklik ve Belirsizlige Tahammülsüzlügün Aracilik Rolü.

OBJECTIVE: In this study, we aimed to evaluate the relationship between fear of COVID-19, perceived threat of COVID-19, anxiety, cognitive control/flexibility, and intolerance to uncertainty. In addition, the mediating role of cognitive control/flexibility and intolerance to uncertainty were investigated. METHOD: 224 volunteers aged between 18-55 years were included in the study. Cognitive Control and Felxibility Scale, Intolerance of Uncertainty Scale, Fear of COVID-19 Scale, Perceived COVID-19 Threat Form and Beck Anxiety Scales were administered to all participants via an online environment. In this context, Pearson correlation, linear regression, and mediation analyzes were performed. RESULTS: There were significant relationships among Cognitive Control and Flexibility, Intolerance of Uncertainty, Beck Anxiety, fear of COVID-19, perceived COVID-19 threat (p<0,01). Linear regression analysis showed that the Beck Anxiety Scale, Intolerance of Uncertainty and Cognitive Control/ Flexibility Scale scores significantly predicted fear of COVID-19 and the perceived threat of COVID-19 (p<0,001). In addition, mediation analysis revealed that intolerance to uncertainty and cognitive control/flexibility are mediating factors between anxiety and the perceived threat of COVID-19 (p<0,01). CONCLUSION: There is a relationship between fear of COVID-19 and perception of threat, anxiety, intolerance of uncertainty, and cognitive control mechanisms. In accordance with these findings, psychosocial support and therapy programs can be created based on cognitive control/flexibility and intolerance of uncertainty in order to increase the mental health well-being of individuals.

Functional magnetic resonance imaging study during resting state and visual oddball task in mild cognitive impairment.

BACKGROUND: Amnestic mild cognitive impairment (aMCI) is a transitional state between normal aging and dementia, and identifying early biomarkers is crucial for disease detection and intervention. Functional magnetic resonance imaging (fMRI) has the potential to identify changes in neural activity in MCI. METHODS: We investigated neural activity changes in the visual network of the aMCI patients (n:20) and healthy persons (n:17) using resting-state fMRI and visual oddball task fMRI. We used independent component analysis to identify regions of interest and compared the activity between groups using a false discovery rate correction. RESULTS: Resting-state fMRI revealed increased activity in the areas that have functional connectivity with the visual network, including the right superior and inferior lateral occipital cortex, the right angular gyrus and the temporo-occipital part of the right middle temporal gyrus (p-FDR = 0.008) and decreased activity in the bilateral thalamus and caudate nuclei, which are part of the frontoparietal network in the aMCI group (p-FDR = 0.002). In the visual oddball task fMRI, decreased activity was found in the right frontal pole, the right frontal orbital cortex, the left superior parietal lobule, the right postcentral gyrus, the right posterior part of the supramarginal gyrus, the right superior part of the lateral occipital cortex, and the right angular gyrus in the aMCI group. CONCLUSION: Our results suggest the alterations in the visual network are present in aMCI patients, both during resting-state and task-based fMRI. These changes may represent early biomarkers of aMCI and highlight the importance of assessing visual processing in cognitive impairment. However, future studies with larger sample sizes and longitudinal designs are needed to confirm these findings.

Associations Between Blood Levels of NLRP3 Inflammasome Components and Obsessive Compulsive Disorder.

Introduction: Even though the effect of inflammation on pathogenesis of obsessive compulsive disorder (OCD) is known, information regarding the underlying mechanisms are yet to be revealed. The NLRP3 inflammasome complex is an important component of the innate immune system that initiates and mediates inflammatory response to a variety of stimuli. This study aims to inquire into a possible association between NLRP3 inflammasome complex and OCD. Methods: This case-control study included 103 participants (51 cases with OCD and 52 healthy controls). All participants were evaluated with the Yale Brown Obsessive Compulsive Scale, Hamilton Depression Scale, and Hewitt Multidimensional Perfectionism Scale. RNA and proteins were extracted from peripheral blood mononuclear cells. Expression of NLRP3 inflammasome components were determined using quantitative real-time polymerase chain reaction (PCR) and Western blotting. Levels of Serum IL-1beta and IL-18 cytokine were determined by ELISA. Results: NEK7 and CASP1 mRNA levels were significantly higher in OCD patients, compared to controls. Pro-caspase-1 protein levels were elevated, as well. Regression analysis showed that NEK7 mRNA and pro-caspase-1 protein levels can differentiate OCD and healthy control groups. Conclusion: Our results provide insight into the molecular alterations that could explain the inflammation-OCD association.