High-homogeneity functional parcellation of human brain for investigating robust functional connectivity

Impaired functional default mode network in patients with mild neurological Wilson’s disease

ObjectivesUnderstanding functional connectivity after consuming meat can be essential to fully understanding consumer’s preferences and the connection to certain flavor compounds. The objective of this study was to determine differences in the functional brain connectivity of consumers after consuming grass-fed beef, grain-fed beef and chicken while determining the different chemical and volatile components that differentiate the treatments.Materials and MethodsGrass-fed strip steaks, Grain-fed strip steaks and chicken breasts were collected, aged 21 d and cut into 1×1-inch consumer steaks. Each steak was vacuum sealed with a random identification number and frozen at –20°C. 23 volunteered consumers evaluated each treatment randomly followed by a Blood Oxygen Level-Dependent (BOLD) fMRI scan. Each consumer received a resting state scan and three scans following each sample. The beef was cooked to a medium degree of doneness (71°C) and the chicken was cooked to a well-done degree of doneness (75°C), followed by a 1-min resting period. The consumers were asked to complete a sensory ballot for each sample to quantify tenderness, juiciness, flavor, overall liking and quality. Each attribute was evaluated on a 100mm line scale. The sensory ballot, volatile and fatty acid data were analyzed by ANOVA and multiple means comparison using SAS while the fMRI data were analyzed using FSL’s FEAT software.ResultsThe results indicated all treatments were equal for tenderness and flavor, but the chicken was the least juicy (P < 0.05) and the grain-fed steak was ranked higher for overall liking (P < 0.05) in comparison to chicken. Furthermore, based on an independent component analysis, there was a significant difference in the functional connectivity (P < 0.05) from the resting state scan to all three treatments within the insular, medial prefrontal cortex, and amygdala regions. Additionally, there were significant differences in connectivity (P < 0.05) between the insula and orbitofrontal cortex in grass-fed compared to grain-fed beef. These areas are involved in processing sensory characteristics related to smell and taste and tend to track differences in preferences and stimulus value. Also, the samples were evaluated for volatile compounds with GC–MS and fatty acids using the FAMES method. Chicken and grass-fed beef was found to have a higher concentration (P < 0.05) of dimethyl sulfone in comparison to grain-fed beef, while the grass-fed steaks possessed a higher concentration (P < 0.05) of toluene in comparison to grain-fed steaks, but not differing from chicken. Dimethyl sulfone and toluene have been tied to grass-fed beef and chicken flavor profiles (Tansawat et al., 2013).ConclusionThe results from the functional brain connectivity in the reward pathways and the chemical components of the different treatments indicated a trend for grain-fed beef to be the most different from grass-fed beef and chicken. Moreover, tying brain activity to the flavor and chemical components in meat can be vital in understanding consumer’s preferences not observed in behavior alone. Therefore, these results can provide a basis to determine the ability to track reactions within the functional connectivity in the brain and the chemical aspects of different steaks to determine and understand consumer’s preferences and the true value of beef and chicken.

Dynamic functional connectivity reveals hyper-connected pattern and abnormal variability in freezing of gait of Parkinson's disease

Evidence on the harms and benefits of social media use is mixed, in part because the effects of social media on well-being depend on a variety of individual difference moderators. Here, we explored potential neural moderators of the link between time spent on social media and subsequent negative affect. We specifically focused on the strength of correlation among brain regions within the frontoparietal system, previously associated with the top-down cognitive control of attention and emotion. Participants (N = 54) underwent a resting state functional magnetic resonance imaging scan. Participants then completed 28 days of ecological momentary assessment and answered questions about social media use and negative affect, twice a day. Participants who spent more than their typical amount of time on social media since the previous time point reported feeling more negative at the present moment. This within-person temporal association between social media use and negative affect was mainly driven by individuals with lower resting state functional connectivity within the frontoparietal system. By contrast, time spent on social media did not predict subsequent affect for individuals with higher frontoparietal functional connectivity. Our results highlight the moderating role of individual functional neural connectivity in the relationship between social media and affect.

Despite advances in resting state functional magnetic resonance imaging investigations, clinicians remain with the challenge of how to implement this paradigm on an individualized basis. Here, we assessed the clinical relevance of resting state functional magnetic resonance imaging acquisitions in patients with disorders of consciousness by means of a systems-level approach. Three clinical centres collected data from 73 patients in minimally conscious state, vegetative state/unresponsive wakefulness syndrome and coma. The main analysis was performed on the data set coming from one centre (Liège) including 51 patients (26 minimally conscious state, 19 vegetative state/unresponsive wakefulness syndrome, six coma; 15 females; mean age 49 ± 18 years, range 11-87; 16 traumatic, 32 non-traumatic of which 13 anoxic, three mixed; 35 patients assessed >1 month post-insult) for whom the clinical diagnosis with the Coma Recovery Scale-Revised was congruent with positron emission tomography scanning. Group-level functional connectivity was investigated for the default mode, frontoparietal, salience, auditory, sensorimotor and visual networks using a multiple-seed correlation approach. Between-group inferential statistics and machine learning were used to identify each network's capacity to discriminate between patients in minimally conscious state and vegetative state/unresponsive wakefulness syndrome. Data collected from 22 patients scanned in two other centres (Salzburg: 10 minimally conscious state, five vegetative state/unresponsive wakefulness syndrome; New York: five minimally conscious state, one vegetative state/unresponsive wakefulness syndrome, one emerged from minimally conscious state) were used to validate the classification with the selected features. Coma Recovery Scale-Revised total scores correlated with key regions of each network reflecting their involvement in consciousness-related processes. All networks had a high discriminative capacity (>80%) for separating patients in a minimally conscious state and vegetative state/unresponsive wakefulness syndrome. Among them, the auditory network was ranked the most highly. The regions of the auditory network which were more functionally connected in patients in minimally conscious state compared to vegetative state/unresponsive wakefulness syndrome encompassed bilateral auditory and visual cortices. Connectivity values in these three regions discriminated congruently 20 of 22 independently assessed patients. Our findings point to the significance of preserved abilities for multisensory integration and top-down processing in minimal consciousness seemingly supported by auditory-visual crossmodal connectivity, and promote the clinical utility of the resting paradigm for single-patient diagnostics.

ObjectivesThe distribution of pathology in neurodegenerative disease can be predicted by the organizational characteristics of white matter in healthy brains. However, we have very little evidence for the impact these pathological changes have on brain function. Understanding any such link between structure and function is critical for understanding how underlying brain pathology influences the progressive behavioral changes associated with neurodegeneration. Here, we demonstrate such a link between structure and function in individuals with premanifest Huntington's.MethodsUsing diffusion tractography and resting state functional magnetic resonance imaging to characterize white matter organization and functional connectivity, we investigate whether characteristic patterns of white matter organization in the healthy human brain shape the changes in functional coupling between brain regions in premanifest Huntington's disease.ResultsWe find changes in functional connectivity in premanifest Huntington's disease that link directly to underlying patterns of white matter organization in healthy brains. Specifically, brain areas with strong structural connectivity show decreases in functional connectivity in premanifest Huntington's disease relative to controls, while regions with weak structural connectivity show increases in functional connectivity. Furthermore, we identify a pattern of dissociation in the strongest functional connections between anterior and posterior brain regions such that anterior functional connectivity increases in strength in premanifest Huntington's disease, while posterior functional connectivity decreases.InterpretationOur findings demonstrate that organizational principles of white matter underlie changes in functional connectivity in premanifest Huntington's disease. Furthermore, we demonstrate functional antero–posterior dissociation that is in keeping with the caudo–rostral gradient of striatal pathology in HD.

Many unsupervised methods are widely used for parcellating the brain. However, unsupervised methods aren’t able to integrate prior information, obtained from such as exiting functional neuroanatomy studies, to parcellate the brain, whereas the prior information guided semi-supervised method can generate more reliable brain parcellation. In this study, we propose a novel semi-supervised clustering method for parcellating the brain into spatially and functionally consistent parcels based on resting state functional magnetic resonance imaging (fMRI) data. Particularly, the prior supervised and spatial information is integrated into spectral clustering to achieve reliable brain parcellation. The proposed method has been validated in the hippocampus parcellation based on resting state fMRI data of 20 healthy adult subjects. The experimental results have demonstrated that the proposed method could successfully parcellate the hippocampus into head, body and tail parcels. The distinctive functional connectivity patterns of these parcels have further demonstrated the validity of the parcellation results. The effects of aging on the three hippocampus parcels’ functional connectivity were also explored across the healthy adult subjects. Compared with state-of-the-art methods, the proposed method had better performance on functional homogeneity. Furthermore, the proposed method had good test–retest reproducibility validated by parcellating the hippocampus based on three repeated resting state fMRI scans from 24 healthy adult subjects.

Phenylketonuria (PKU) is an autosomal recessive condition characterized by a deficiency in the enzyme phenylalanine hydroxylase (PAH), which is necessary for the metabolism of the amino acid phenylalanine (Phe) into tyrosine. When left untreated, PKU is associated with significant neurological and cognitive sequelae. Individuals who are diagnosed early and begin treatment shortly after birth (i.e., early-treated PKU; ETPKU) avoid the significant impairments associated with untreated PKU. However, neurological and neurocognitive disruptions are still noted in this population. Even with the accumulated evidence for disruptions in WM integrity, functional connectivity, and neurocognition, the relationship between these sequelae is not well understood. Resting state functional magnetic resonance imaging (fMRI), diffusion tensor imaging (DTI), and neurocognitive data from 35 adults with ETPKU and a demographically similar comparison group of 32 adults without PKU was analyzed. White matter abnormalities were evidenced by significant reductions in axial diffusivity (AD) among individuals with PKU across several connections within the default mode network (DMN). Within the ETPKU group, recent Phe levels were significantly correlated with AD. Several significant correlations between AD and the neurocognitive composites were identified, although the mediation model relating Phe levels, structural connectivity, and cognition was not supported. Functional connectivity within the DMN was also reduced in the ETPKU group but showed no relationship with Phe levels. Although functional connectivity significantly correlated with structural connectivity in the non-PKU group, non-significant relationships were found among those with ETPKU. The present findings underscore the importance of metabolic control and provides insight into the possible mechanisms underlying neurological and cognitive changes associated with ETPKU. Additionally, the present work suggests that the relationship between functional and structural connectivity is more complicated than in unaffected populations.

Single-dose serotonergic stimulation shows widespread effects on functional brain connectivity

Brain Connectivity: A Journal of Clinical Neurology, Neuroscience, and Neuroimaging Advancing the Field of Neurology.

Physical activity (PA) plays an important role in affect processing. Studies describe the orbitofrontal cortex (OFC) as a major hub for emotion processing and the pathophysiology of affective disorders. Subregions of the OFC show diverse functional connectivity (FC) topographies, but the effect of chronic PA on subregional OFC FC still lacks scientific understanding. Therefore, we aimed at investigating the effects of regular PA on the FC topographies of OFC subregions in healthy individuals within a longitudinal randomized controlled exercise study. Participants (age: 18–35 years) were randomly assigned to either an intervention group (IG; N = 18) or a control group (CG; N = 10). Fitness assessments, mood questionnaires, and resting state functional magnetic resonance imaging (rsfMRI) were performed four times over the duration of 6 months. Using a detailed parcellation of the OFC, we created subregional FC topography maps at each time point and applied a linear mixed model to assess the effects of regular PA. The posterior–lateral right OFC showed a group and time interaction, revealing decreased FC with the left dorsolateral prefrontal cortex in the IG, while FC in the CG increased. Group and time interaction in the anterior–lateral right OFC with the right middle frontal gyrus was driven by increased FC in the IG. The posterior–lateral left OFC showed a group and time interaction based on differential change in FC to the left postcentral gyrus and the right occipital gyrus. This study emphasized regionally distinctive FC changes induced by PA within the lateral OFC territory, while providing aspects for further research.

The human entorhinal-hippocampal circuitry is characterized by an information-specific functional organization where two routes, that are preferentially connected to the parahippocampal cortex or the perirhinal and retrosplenial cortices, divide the entorhinal cortex as well as hippocampal subiculum and CA1 subregions.

2601 A model for simple cortical cells with lagged/nonlaggd LGN inputs

Disrupted functional connectivity of default mode and salience networks in chronic pancreatitis patients

Objective To explore the alterations of hippocampal functional connectivity in patients with intractable temporal lobe epilepsy (ITLE) with resting state functional magnetic resonance imaging (rs-fMRI).Methods Eighteen patients with ITLE,admitted to our hospital from August 2013 to May 2014,and 18 healthy controls were chosen in our study; the fMRI data of the two groups were obtained; analysis of the resting state brain functional connectivity was performed by choosing the left and right hippocampus as the regions of interest (ROIs),and then,the differences of hippocampal functional connectivity were compared between ITLE group and healthy control group.Results When the left hippocampus was selected as ROI,significantly enhanced functional connectivity in the ITLE group was observed in the right cuneus,significantly weakened functional connectivity in the ITLE group was observed in the bilateral caudate nucleus,bilateral septal area and right gyrus rectus,as compared with those in the healthy control group (P＜0.05); when the right hippocampus was selected as ROI,significantly enhanced functional connectivity in the ITLE group was observed in the bilateral cuneus,bilateral lingual gyrus,and left calcarine,significantly weakened functional connectivity in the ITLE group was observed in the bilateral superior temporal gyrus,right middle temporal gyrus,left supramarginal gyrus,left precentral gyrus and left postcentral gyrus,as compared with those in the healthy control group (P＜0.05).Conclusion Hippocampal dysfunction of patients with ITLE could be found based on rs-fMRI,which prompts that the hippocampus plays an important role in the epilepsy network of patients with ITLE. Key words: Temporal lobe epilepsy; Functional magnetic resonance imaging; Functional connectivity; Hippocampus