Objectives: The aim of this study was to evaluate brain activity in youth during chewing gum and wood stick using functional magnetic resonance imaging (fMRI). Methods: Two participants chewed wax gums and wood stick on the rhythm of 1 Hz during MRI scanning. The task paradigm was a block design and each chewing-rest procedure was repeated five times for 30s. Results: The brain regions activated during chewing gum and wood stick were the precentral gyrus, postcentral gyrus, supplementary motor area, thalamus cerebellum. The medial prefrontal cortex (mPFC), anterior cingulate cortex (ACC), hippocampus, and precuneus were additionally activated by mastication of the wood stick. Brain activation induced by chewing wood stick was higher than chewing gum. Conclusions Our results suggest that mastication contribute to cognitive improvement through brain activity, this effect is stronger during chewing wood than gum. Therefore, eating harder foods may improve cognitive function more effectively.

Objectives: Maltreatment experiences can alter brain function related to emotion regulation, such as cognitive reappraisal. While dysregulation of emotion is an important risk factor to mental health problems in maltreated people, studies reported alterations in brain networks related to cognitive reappraisal are still lacking. Methods: Twenty-seven healthy subjects were recruited in this study. The maltreatment experiences and positive reappraisal abilities were measured using the Childhood Trauma Questionnaire-Short Form and the Cognitive Emotion Regulation Questionnaire, respectively. Twelve subjects reported one or more moderate maltreatment experiences. Subjects were re-exposed to pictures after the cognitive reappraisal task using the International Affective Picture System during fMRI scan. Results: The maltreatment group reported more negative feelings on negative pictures which tried cognitive reappraisal than the no-maltreatment group (p < 0.05). Activities in the right superior marginal gyrus and right middle temporal gyrus were higher in the maltreatment group (uncorrected p < 0.001, cluster size > 20). Conclusions We found that paradoxical activities in semantic networks were shown in the victims of maltreatment. Further study might be needed to clarify these aberrant functions in semantic networks related to maltreatment experiences.

Objective: Recent studies highlighted the triple-network model which illustrated the interactions among three large-scale networks including salience network (SN). The functional magnetic resonance imaging used in this study was designed to investigate the characteristics of three large-scale networks associated with the thought-action fusion (TAF) in patients with obsessive-compulsive disorder (OCD) using power spectral density (PSD) analysis. Methods: This study included 32 OCD patients and 38 age-matched healthy controls (HC). The TAF task was modified from the experiment of Rassin. PSD from time courses in large-scale networks of each subject was measured to compare between the groups for both TAF and resting state. Results: In SN, OCD reported lower power in the low-frequency domain of SN compared to HC using the two-sample t test during the TAF task (t = −2.395, p = 0.019) but not in the resting state. The PSD in the low-frequency domain of the SN had a significant negative correlation with state score in the guilty inventory (r = −0.361, p = 0.042) in OCD patients. Conclusion This study suggests that OCD patients showed reduced SN power which can be prominent in a certain situation, such as TAF. In addition, the PSD alterations in SN cause difficulty in processing ambiguous emotional cues in social situations, and the difficulty can be connected with a negative feeling (e.g., guilt).

Purpose: The survival of organisms critically depends on avoidance responses to lifethreatening stimuli. Information about dangerous situations needs to be remembered to produce defensive behavior. To investigate underlying brain regions to process information of danger, manganese-enhanced MRI (MEMRI) was used in olfactory fear-conditioned rats. Materials and Methods: Fear conditioning was conducted in male Sprague-Dawley rats. The animals received nasal injections of manganese chloride solution to monitor brain activation for olfactory information processing. Twenty-four hours after manganese injection, rats were exposed to electric foot shocks with odor cue for one hour. Control rats were exposed to the same odor cue without foot shocks. Fortyeight hours after the conditioning, rats were anesthetized and their brains were scanned with 9.4T MRI. Acquired images were processed and statistical analyses were performed using AFNI. Results: Manganese injection enhanced brain areas involved in olfactory information pathways in T1 weighted images. Rats that received foot shocks showed higher brain activation in the central nucleus of the amygdala, septum, primary motor cortex, and preoptic area. In contrast, control rats displayed greater signals in the orbital cortex and nucleus accumbens. Conclusion Nasal delivery of manganese solution enhanced olfactory signal pathways in rats. Odor cue paired with foot shocks activated amygdala, the central brain region in fear, and related brain circuits. Use of MEMRI in fear conditioning provides a reliable monitoring technique of brain activation for fear learning.

Objective: Although cognitive models of obsessive-compulsive disorder (OCD) fall into two categories: cognitive deficit models and dysfunctional belief models, these approaches have their own ways and have hardly been reconciled. Therefore, this study aimed to investigate the potential relationships between cognitive deficit (using the Wisconsin Card Sorting Task, WCST) and dysfunctional belief (measured by scales of dysfunctional beliefs) mediated by neural activity in OCD patients. Methods: Thirty OCD patients and 30 healthy participants performed the WCST condition and a baseline MATCH condition during the 3T-functional magnetic resonance imaging (fMRI) acquisition. Results: Engagement of additional frontoparietal networks with poorer performance of WCST was found during the fMRI scan in OCD patients. Selected regions of interest from activated regions have positive relationships with dysfunctional beliefs and with the unacceptable thoughts symptom dimension in the OCD group. Conclusion Findings suggest that alteration in frontoparietal networks related to cognitive deficits can be associated with dysfunctional beliefs while performing conventional neurocognitive tasks and this association with dysfunctional beliefs may be pronounced in the unacceptable thoughts domain-dominant OCD patients.

Objective: Although cognitive models of obsessive-compulsive disorder (OCD) fall into two categories: cognitive deficit models and dysfunctional belief models, these approaches have their own ways and have hardly been reconciled. Therefore, this study aimed to investigate the potential relationships between cognitive deficit (using the Wisconsin Card Sorting Task, WCST) and dysfunctional belief (measured by scales of dysfunctional beliefs) mediated by neural activity in OCD patients. Methods: Thirty OCD patients and 30 healthy participants performed the WCST condition and a baseline MATCH condition during the 3T-functional magnetic resonance imaging (fMRI) acquisition. Results: Engagement of additional frontoparietal networks with poorer performance of WCST was found during the fMRI scan in OCD patients. Selected regions of interest from activated regions have positive relationships with dysfunctional beliefs and with the unacceptable thoughts symptom dimension in the OCD group. Conclusion Findings suggest that alteration in frontoparietal networks related to cognitive deficits can be associated with dysfunctional beliefs while performing conventional neurocognitive tasks and this association with dysfunctional beliefs may be pronounced in the unacceptable thoughts domain-dominant OCD patients.

Objective: Thought-action fusion (TAF), one of the most-studied dysfunctional beliefs in obsessive-compulsive disorder, represents an individual’s belief that his/her thoughts directly influence events. TAF belief types are divided into personal thoughts relating to positive (positive TAF) and negative outcomes (negative TAF). However, the neural mechanisms underlying both aspects of the TAF response remain elusive. Methods: This functional magnetic resonance imaging study aimed to investigate the neural circuits related to positive and negative TAF and their relationships with psychological measures. Thirty-one healthy male volunteers participated in a modified TAF task wherein they were asked to read the name of a close person embedded in positive statements (PS) or negative statements (NS). Results: Conjunction analysis revealed activation of the fusiform and lingual gyri, midcingulate and superior medial frontal gyri, inferior orbitofrontal gyrus, and temporoparietal junction. The NS ＞ PS comparison showed additional activation in the precuneus and medial prefrontal cortex, superior frontal gyrus, insula, globus pallidus, thalamus, and midbrain. Precuneus activity was associated with the TAF score among these areas. Moreover, activity in the inferior orbitofrontal gyrus, insula, superior, middle and medial frontal gyri, globus pallidus, inferior parietal lobule, and precuneus was associated with dimensional obsessive-compulsive scores. In contrast, the PS ＞ NS comparison revealed no significant activation. Conclusion These results suggest that negative TAF, relative to positive TAF, recruits additional regions for self-referential processing, salience, and habitual responding, which may contribute to the activation of the belief that a negative thought increases the probability of that negative outcome.

Gadolinium contrast agents (CAs) are integral components of clinical magnetic resonance imaging (MRI). However, safety concerns have arisen regarding the use of gadolinium CAs, due to their association with nephrogenic systemic fibrosis (NSF). Furthermore, recently the long-term retention of Gd²⁺-based CAs in brains patients with normal renal function raised another possible safety issue. The safety concerns of Gd²⁺-based CAs have been based on the ligand structure of Gd²⁺-based CAs, and findings that Gd²⁺-based CAs with linear ligand structures showed much higher incidences of NSF and brain retention of CAs than Gd²⁺-based CAs with macrocyclic ligand structure. In the current study, we report the in vivo biodistribution profile of a new highly stable multifunctional Gd²⁺-based CA, with macrocyclic ligand structure (HNP-2006). MR imaging using HNP-2006 demonstrated a significant contrast enhancement in many different organs. Furthermore, the contrast enhanced tumor imaging using HNP-2006 confirmed that this new macrocyclic CA can be used for detecting tumor in the central nervous system. Therefore, this new multifunctional HNP-2006 with macrocyclic ligand structure shows great promise for whole-body clinical application.
Brain ; Central Nervous System ; Contrast Media ; Gadolinium ; Humans ; Incidence ; Magnetic Resonance Imaging ; Nephrogenic Fibrosing Dermopathy

PURPOSE: To report the use of multiband accelerated echo-planar imaging (EPI) for resting-state functional MRI (rs-fMRI) to achieve rapid high temporal resolution at 3T compared to conventional EPI. MATERIALS AND METHODS: rs-fMRI data were acquired from 20 healthy right-handed volunteers by using three methods: conventional single-band gradient-echo EPI acquisition (Data 1), multiband gradient-echo EPI acquisition with 240 volumes (Data 2) and 480 volumes (Data 3). Temporal signal-to-noise ratio (tSNR) maps were obtained by dividing the mean of the time course of each voxel by its temporal standard deviation. The resting-state sensorimotor network (SMN) and default mode network (DMN) were estimated using independent component analysis (ICA) and a seed-based method. One-way analysis of variance (ANOVA) was performed between the tSNR map, SMN, and DMN from the three data sets for between-group analysis. P < 0.05 with a family-wise error (FWE) correction for multiple comparisons was considered statistically significant. RESULTS: One-way ANOVA and post-hoc two-sample t-tests showed that the tSNR was higher in Data 1 than Data 2 and 3 in white matter structures such as the striatum and medial and superior longitudinal fasciculus. One-way ANOVA revealed no differences in SMN or DMN across the three data sets. CONCLUSION: Within the adapted metrics estimated under specific imaging conditions employed in this study, multiband accelerated EPI, which substantially reduced scan times, provides the same quality image of functional connectivity as rs-fMRI by using conventional EPI at 3T. Under employed imaging conditions, this technique shows strong potential for clinical acceptance and translation of rs-fMRI protocols with potential advantages in spatial and/or temporal resolution. However, further study is warranted to evaluate whether the current findings can be generalized in diverse settings.
Dataset ; Echo-Planar Imaging* ; Magnetic Resonance Imaging* ; Methods ; Signal-To-Noise Ratio ; Volunteers ; White Matter

The aims of this study were to develop strategies and algorithms of calculating food commodity intake suitable for exposure assessment of residual chemicals by using the food intake database of Korea National Health and Nutrition Examination Survey (KNHANES). In this study, apples and their processed food products were chosen as a model food for accurate calculation of food commodity intakes uthrough the recently developed Korea food commodity intake calculation (KFCIC) software. The average daily intakes of total apples in Korea Health Statistics were 29.60 g in 2008, 32.40 g in 2009, 34.30 g in 2010, 28.10 g in 2011, and 24.60 g in 2012. The average daily intakes of apples by KFCIC software was 2.65 g higher than that by Korea Health Statistics. The food intake data in Korea Health Statistics might have less reflected the intake of apples from mixed and processed foods than KFCIC software has. These results can affect outcome of risk assessment for residual chemicals in foods. Therefore, the accurate estimation of the average daily intake of food commodities is very important, and more data for food intakes and recipes have to be applied to improve the quality of data. Nevertheless, this study can contribute to the predictive estimation of exposure to possible residual chemicals and subsequent analysis for their potential risks.
Eating ; Korea* ; Malus ; Nutrition Surveys* ; Risk Assessment