Diffusion properties of the fornix assessed by deterministic tractography shows age, sex, volume, cognitive, hemispheric, and twin relationships in young adults from the Human Connectome Project

Abstract The endocannabinoid system serves a critical role in homeostatic regulation through its influence on processes underlying appetite, pain, reward, and stress, and cannabis has long been used for the related modulatory effects it provides through tetrahydrocannabinol (THC). We investigated how THC exposure relates to tissue microstructure of the cerebral cortex and subcortical nuclei using computational modeling of diffusion magnetic resonance imaging data in a large cohort of young adults from the Human Connectome Project. We report strong associations between biospecimen-defined THC exposure and microstructure parameters in discrete gray matter brain areas, including frontoinsular cortex, ventromedial prefrontal cortex, and the lateral amygdala subfields, with independent effects in behavioral measures of memory performance, negative intrusive thinking, and paternal substance abuse. These results shed new light on the relationship between THC exposure and microstructure variation in brain areas related to salience processing, emotion regulation, and decision making. The absence of effects in some other cannabinoid-receptor-rich brain areas prompts the consideration of cellular and molecular mechanisms that we discuss. Further studies are needed to characterize the nature of these effects across the lifespan and to investigate the mechanistic neurobiological factors connecting THC exposure and microstructural parameters.

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146 Prefrontal Cortical Connectivity-Based Segmentation of the Anterior Limb of the Internal Capsule: Implications for Stereotactic Targeting for Refractory OCD

Neurosurgery ◽

10.1093/neuros/nyx417.146 ◽

2017 ◽

Vol 64 (CN_suppl_1) ◽

pp. 235-235

Author(s):

Pranav Nanda MPhil ◽

Garrett P Banks ◽

Justin Oh ◽

Yagna Pathak ◽

Sameer A Sheth

Keyword(s):

Diffusion Tensor ◽

Behavioral Therapy ◽

Internal Capsule ◽

Lesion Volume ◽

Obsessive Compulsive ◽

Compulsive Disorder ◽

Prefrontal Cortical ◽

Human Connectome Project ◽

Deterministic Tractography ◽

Diffusion Tensor Imaging Dti

Abstract INTRODUCTION Although most patients with obsessive-compulsive disorder (OCD) are well controlled with pharmacological and cognitive behavioral therapy, 10–20% remain severe and refractory. Stereotactic targeting of the anterior limb of the internal capsule (ALIC) has been used for decades to treat these patients. However, there is uncertainty about optimal targeting within the ALIC, as different locations appear to have variable efficacy. Using diffusion tensor imaging (DTI), we segmented the ALIC based on prefrontal connectivity to evaluate the effect of various stereotactic targets. METHODS ALIC segmentations based on frontal Brodmann area (BA) connectivity were generated and combined for 40 subjects from the Human Connectome Project (HCP) using connectivity-based seed classification. Literature review revealed five stereotactic targets within the ALIC. Targets were modeled as 5 mm spheres and were evaluated for overlap with various DTI-defined ALIC segments. Deterministic tractography was performed on an 842-subject HCP DTI template using modeled targets as seeds to identify involved connectomic networks. RESULTS >All 40 ALIC segmentations exhibited a dorsal-ventral axis of organization. On average, the combined segmentation was accurate for 66.2% of individuals. The region assigned to BA11 (orbitofrontal cortex, OFC) exhibited the greatest consistency across individuals, with 12.1% being consistently assigned in all 40 subjects. According to the segmentation, a mean of 63.9% of modeled lesion volume within the ALIC intersected with the BA11 region. All five modeled targets exhibited connectivity to OFC in the 842-subject HCP template. CONCLUSION These results clarify the organization and variability of the ALIC. This variability suggests that patients may benefit from pre-operative tractography for individualized targeting, although current stereotactic targets tend to involve the most consistent ALIC subregions. These findings also suggest that stereotactic targeting for OCD likely involves modulation of prefrontal-subcortical tracts connecting the OFC, which bears relevance to the cortico-striato-thalamo-cortical (CSTC) model of OCD pathophysiology.

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Valuation System connectivity is correlated with poly-drug use in young adults

10.1101/2020.11.17.20233601 ◽

2020 ◽

Author(s):

Kavinash Loganathan ◽

Jinglei Lv ◽

Vanessa Cropley ◽

Andrew Zalesky ◽

Eric Tatt Wei Ho

Keyword(s):

Substance Use ◽

Young Adults ◽

Drug Use ◽

Network Connectivity ◽

Demographic Variables ◽

Complex Model ◽

Stimulant Use ◽

Human Connectome Project ◽

Neuroimaging Data ◽

Other Substances

AbstractPoly-drug consumption is a dangerous, yet complex model of substance use that contributes to many cases of imprisonment and fatal overdose. Despite the growing number of studies looking at this phenomenon, there remains a lack of neuroimaging data elucidating the neural markers of poly-drug use. In particular, the valuation system, tasked with weighing the value of items and experiences, may hold significance in understanding the motivations behind poly-drug use. To this end, we sought to analyze the functional connectivity of the Valuation System (VS), Executive Control System (ECS) and Valuation-Control Complex (VCC) of drug-using participants in the Human Connectome Project Healthy Young Adult dataset (n=992). Using multivariate regression, network-averaged connectivities were correlated with various substance use measures (stimulants, cocaine, hallucinogens, opiates, sedatives and marijuana) and demographic variables (gender, parental use history). We found that the VS, ECS and VCC were all correlated with drug use behaviour either as individual systems or when paired with other substances. Both VS (R2= 0.53) and ECS (R2= 0.55) connectivity are positively correlated with stimulant use whereas both ECS (R2= 0.45) and VCC (R2= 0.045) connectivity are negatively correlated with marijuana use. VS (R2= 0.75) and VCC (R2= 0.74) connectivities are also negatively correlated with sedative use. Additionally, network connectivity was correlated with drug use behaviour via two-way interactions with other substances. These findings provide preliminary indications of the consequences of poly-drug use in healthy young adults.

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Delay Discounting and Neurocognitive Performance in Young Adults with Differential Patterns of Substance Use: Findings from the Human Connectome Project

10.31234/osf.io/vyr5m ◽

2021 ◽

Author(s):

Gideon Peter Naudé ◽

Derek D Reed ◽

Justin Charles Strickland ◽

Michael Amlung

Keyword(s):

Young Adults ◽

Alcohol Use ◽

Delay Discounting ◽

Neurocognitive Performance ◽

Dual Use ◽

Multivariate Tests ◽

Demographic Indicators ◽

Polysubstance Use ◽

Human Connectome Project ◽

Other Substances

A large proportion of individuals who use psychoactive substances regularly use more than one substance. This pattern of behavior, termed polysubstance use, is associated with greater risks than when consuming only single substance. The present study examined delay discounting, neurocognitive functioning, and demographic indicators among a large, racially and socioeconomically diverse sample of young adults drawn from the Human Connectome Project who reported either non, mono, or dual use of alcohol, tobacco and/or cannabis. Univariate and multivariate tests suggested individuals who reported using multiple substances were more likely to be male, experienced higher rates of alcohol use disorder, and, when reporting both alcohol use and cannabis involvement, scored lower on a measure of inhibitory control relative to those who reported mono or dual use of alcohol and/or cigarettes. Individuals who reported currently smoking cigarettes exhibited the steepest discounting irrespective of other substances used; however, we observed additive effects for alcohol use and, to a lesser extent, cannabis involvement. Specifically, steeper discounting occurred when individuals who reported either regular alcohol use or >100 lifetime instances of cannabis use also reported smoking cigarettes. We discuss several hypotheses for this finding related to the diversity of the sample and substances assessed as well as directions for future programmatic lines of research.

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Integrating multimodal connectivity improves prediction of individual cognitive abilities

10.1101/2020.06.25.172387 ◽

2020 ◽

Author(s):

Elvisha Dhamala ◽

Keith W. Jamison ◽

Abhishek Jaywant ◽

Sarah Dennis ◽

Amy Kuceyeski

Keyword(s):

Cognitive Abilities ◽

Structural Information ◽

Brain Connectivity ◽

Structural Connectivity ◽

Secondary Analysis ◽

Learning Approaches ◽

Activation Patterns ◽

Verbal Language ◽

Human Connectome Project ◽

Deterministic Tractography

SummaryHow white matter pathway integrity and neural co-activation patterns in the brain relate to complex cognitive functions remains a mystery in neuroscience. Here, we integrate neuroimaging, connectomics, and machine learning approaches to explore how multimodal brain connectivity relates to cognition. Specifically, we evaluate whether integrating functional and structural connectivity improves prediction of individual crystallised and fluid abilities in 415 unrelated healthy young adults from the Human Connectome Project. Our primary results are two-fold. First, we demonstrate that integrating functional and structural information – at both a model input or output level – significantly outperforms functional or structural connectivity alone to predict individual verbal/language skills and fluid reasoning/executive function. Second, we show that distinct pairwise functional and structural connections are important for these predictions. In a secondary analysis, we find that structural connectivity derived from deterministic tractography is significantly better than structural connectivity derived from probabilistic tractography to predict individual cognitive abilities.

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TractEM: Fast Protocols for Whole Brain Deterministic Tractography-Based White Matter Atlas

10.1101/651935 ◽

2019 ◽

Author(s):

Roza G. Bayrak ◽

Xuan Wang ◽

Kurt G. Schilling ◽

Jasmine M. Greer ◽

Colin B. Hansen ◽

...

Keyword(s):

White Matter ◽

Correlation Coefficient ◽

Mean Squared Error ◽

Intraclass Correlation ◽

Structural Connectivity ◽

Fiber Bundles ◽

Initial Stage ◽

Human Connectome Project ◽

Baltimore Longitudinal Study ◽

Deterministic Tractography

AbstractReproducible identification of white matter tracts across subjects is essential for the study of structural connectivity of the human brain. The key challenges are anatomical differences between subjects and human rater subjectivity in labeling. Labeling white matter regions of interest presents many challenges due to the need to integrate both local and global information. Clearly communicating the human/manual processes to capture this information is cumbersome, yet essential to lay a solid foundation for comprehensive atlases. The state-of-the-art for white matter atlas is the single population-averaged Johns Hopkins Eve atlas. A critical bottleneck with the Eve atlas framework is that manual labeling time is extensive and peripheral white matter regions are conservatively labeled. In this work, we developed protocols that will facilitate manual virtual dissection of white matter pathways, with the goals to be anatomically accurate, intuitive, reproducible, and act as an initial stage to build an amenable knowledge base of neuroanatomical regions. We analyzed reproducibility of the fiber bundles and variability of human raters using DICE correlation coefficient, intraclass correlation coefficient, and root mean squared error. The protocols at their initial stage have shown promising results on both typical 3T research acquisition Baltimore Longitudinal Study of Aging and high-acquisition quality Human Connectome Project datasets. The TractEM manual labeling protocols allow for reconstruction of reproducible subject-specific fiber bundles across the brain. The protocols and sample results have been made available in open source to improve generalizability and reliability in collaboration.

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Regional structural-functional connectome coupling is heritable and associated with age, sex and cognition in adults

10.1101/2020.12.09.417725 ◽

2020 ◽

Author(s):

Zijin Gu ◽

Keith Wakefield Jamison ◽

Mert Rory Sabuncu ◽

Amy Kuceyeski

Keyword(s):

Young Adults ◽

Coupling Strength ◽

Cognitive Abilities ◽

Large Scale ◽

Functional Connectome ◽

Lingual Gyrus ◽

Human Connectome Project ◽

Subcortical Regions ◽

The Right ◽

The Relationship

ABSTRACTLarge scale white matter brain connections quantified via the structural connectome (SC) act as the backbone for the flow of functional activation, which can be represented via the functional connectome (FC). Many studies have used statistical analysis or computational modeling techniques to relate SC and FC at a global, whole-brain level. However, relatively few studies have investigated the relationship between individual cortical and subcortical regions’ structural and functional connectivity profiles, here called SC-FC coupling, or how this SC-FC coupling may be heritable or related to age, sex and cognitive abilities. Here, we quantify regional SC-FC coupling in a large group of healthy young adults (22 to 37 years) using diffusion-weighted MRI and resting-state functional MRI data from the Human Connectome Project. We find that while regional SC-FC coupling strengths vary widely across cortical, subcortical and cerebellar regions, they were strongest in highly myelinated visual and somatomotor areas. Additionally, SC-FC coupling displayed a broadly negative association with age and, depending on the region, varied across sexes and with cognitive scores. Specifically, males had higher coupling strength in right supramarginal gyrus and left cerebellar regions while females had higher coupling strength in right visual, right limbic and right cerebellar regions. Furthermore, increased SC-FC coupling in the right lingual gyrus was associated with worse cognitive scores. Finally, we found SC-FC coupling to be highly heritable, particularly in the visual, dorsal attention, and fronto-parietal networks, and, interestingly, more heritable than FC or SC alone. Taken together, these results suggest regional structure-function coupling in young adults decreases with age, varies across sexes in a non-systematic way, is somewhat associated with cognition and is highly heritable.

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