scholarly journals High resolution structural and functional MRI of the hippocampus in young adults with Down syndrome

2021 ◽  
Author(s):  
Katherine A Koenig ◽  
Se-Hong Oh ◽  
Melissa R Stasko ◽  
Elizabeth C Roth ◽  
H Gerry Taylor ◽  
...  
Keyword(s):  
Down Syndrome ◽  
Functional Connectivity ◽  
Cortical Thickness ◽  
Right Hemisphere ◽  
Gray Matter Volume ◽  
Drug Efficacy ◽  
Structure And Function ◽  
7 Tesla ◽  
Whole Brain ◽  
And Function

Abstract Down syndrome is the phenotypic consequence of trisomy 21, with clinical presentation including both neurodevelopmental and neurodegenerative components. Although the intellectual disability typically displayed by individuals with Down syndrome is generally global, it also involves disproportionate deficits in hippocampally-mediated cognitive processes. Hippocampal dysfunction may also relate to Alzheimer’s disease-type pathology, which can appear in as early as the first decade of life and becomes universal by age 40. Using 7-tesla MRI of the brain, we present an assessment of the structure and function of the hippocampus in 34 individuals with Down syndrome (mean age 24.5 years ± 6.5) and 27 age- and sex-matched typically developing healthy controls. In addition to increased whole-brain mean cortical thickness and lateral ventricle volumes (p < 1.0 × 10−4), individuals with Down syndrome showed selective volume reductions in bilateral hippocampal subfields CA1, dentate gyrus, and tail (p < 0.005). In the group with Down syndrome, bilateral hippocampi showed widespread reductions in the strength of functional connectivity, predominately to frontal regions (p < 0.02). Age was not related to hippocampal volumes or functional connectivity measures in either group, but both groups showed similar relationships of age to whole-brain volume measures (p < 0.05). Finally, we performed an exploratory analysis of a subgroup of individuals with Down syndrome with both imaging and neuropsychological assessments. This analysis indicated that measures of spatial memory were related to mean cortical thickness, total gray matter volume, and right hemisphere hippocampal subfield volumes (p < 0.02). This work provides a first demonstration of the usefulness of high-field MRI to detect subtle differences in structure and function of the hippocampus in individuals with Down syndrome, and suggests the potential for development of MRI-derived measures as surrogate markers of drug efficacy in pharmacological studies designed to investigate enhancement of cognitive function.

scholarly journals Daily Morning Blue Light Therapy for Post-mTBI Sleep Disruption: Effects on Brain Structure and Function

2021 ◽  
Vol 12 ◽  
Author(s):  
Adam C. Raikes ◽  
Natalie S. Dailey ◽  
Brittany Forbeck ◽  
Anna Alkozei ◽  
William D. S. Killgore
Keyword(s):  
Functional Connectivity ◽  
Brain Structure ◽  
Daytime Sleepiness ◽  
Gray Matter Volume ◽  
Light Therapy ◽  
Structure And Function ◽  
Sleep Disruption ◽  
Matter Volume ◽  
Brain Structure And Function ◽  
And Function

Background: Mild traumatic brain injuries (mTBIs) are associated with novel or worsened sleep disruption. Several studies indicate that daily morning blue light therapy (BLT) is effective for reducing post-mTBI daytime sleepiness and fatigue. Studies demonstrating changes in brain structure and function following BLT are limited. The present study's purpose is to identify the effect of daily morning BLT on brain structure and functional connectivity and the association between these changes and self-reported change in post-mTBI daytime sleepiness.Methods: A total of 62 individuals recovering from a mTBI were recruited from two US cities to participate in a double-blind placebo-controlled trial. Eligible individuals were randomly assigned to undergo 6 weeks of 30 min daily morning blue or placebo amber light therapy (ALT). Prior to and following treatment all individuals completed a comprehensive battery that included the Epworth Sleepiness Scale as a measure of self-reported daytime sleepiness. All individuals underwent a multimodal neuroimaging battery that included anatomical and resting-state functional magnetic resonance imaging. Atlas-based regional change in gray matter volume (GMV) and region-to-region functional connectivity from baseline to post-treatment were the primary endpoints for this study.Results: After adjusting for pre-treatment GMV, individuals receiving BLT had greater GMV than those receiving amber light in 15 regions of interest, including the right thalamus and bilateral prefrontal and orbitofrontal cortices. Improved daytime sleepiness was associated with greater GMV in 74 ROIs, covering many of the same general regions. Likewise, BLT was associated with increased functional connectivity between the thalamus and both prefrontal and orbitofrontal cortices. Improved daytime sleepiness was associated with increased functional connectivity between attention and cognitive control networks as well as decreased connectivity between visual, motor, and attention networks (all FDR corrected p < 0.05).Conclusions: Following daily morning BLT, moderate to large increases in both gray matter volume and functional connectivity were observed in areas and networks previously associated with both sleep regulation and daytime cognitive function, alertness, and attention. Additionally, these findings were associated with improvements in self-reported daytime sleepiness. Further work is needed to identify the personal characteristics that may selectively identify individuals recovering from a mTBI for whom BLT may be optimally beneficial.

scholarly journals Skill acquisition increases myelination and strengthens functional connectivity in the sensorimotor circuit of the adult rat

2019 ◽  
Author(s):  
Cassandra Sampaio-Baptista ◽  
Antoin de Weijer ◽  
Annette van der Toorn ◽  
Willem M. Otte ◽  
Anderson M. Winkler ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Motor Learning ◽  
Skill Acquisition ◽  
Structure And Function ◽  
Skill Learning ◽  
Structural Reorganization ◽  
Adult Rats ◽  
Whole Brain ◽  
And Function

ABSTRACTThe effects of skill acquisition on whole-brain structure and functional networks have been extensively investigated in humans but have yet to be explored in rodents. Forelimb reaching training in rodents results in well-established focal functional and structural reorganization within the motor cortex (M1) and cerebellum, indicating distributed alterations in both structure and function. However, it is unclear how local alterations in structure and function relate to distributed learning-related changes across motor networks. Here we trained adult rats in skilled reaching and used multimodal whole-brain in vivo MRI to assess both structural and functional plasticity over time.We detected increases in a myelin-related MRI metric in white matter, cortical areas, and to a lesser extent in the cerebellum, paralleled by strengthened functional connectivity between M1 and cerebellum, possibly reflecting a decrease in cerebellum inhibition over M1. Skill learning therefore leads to myelin increases in pathways that connect sensorimotor regions, and in functional connectivity increases between areas involved in motor learning, all of which correlate with performance. These findings closely mirror previous reports of network-level changes following motor learning in humans and underlines the correspondence between human and rodent brain circuits for motor learning, despite important differences in the anatomy of physiology of movement circuits between species.

scholarly journals Effects of early ketamine exposure on cerebral gray matter volume and functional connectivity

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Chia-Chun Hung ◽  
Yi-Hsuan Liu ◽  
Chu-Chung Huang ◽  
Cheng-Ying Chou ◽  
Chun-Ming Chen ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Gray Matter ◽  
Brain Structure ◽  
Functional Organization ◽  
Gray Matter Volume ◽  
Structure And Function ◽  
Control Group ◽  
Matter Volume ◽  
Brain Structure And Function ◽  
And Function

Abstract Ketamine has been used for medical purposes, most typically as an anesthetic, and recent studies support its use in the treatment of depression. However, ketamine tends to be abused by adolescents and young adults. In the current study, we examined the effects of early ketamine exposure on brain structure and function. We employed MRI to assess the effects of ketamine abuse on cerebral gray matter volume (GMV) and functional connectivity (FC) in 34 users and 19 non-users, employing covariates. Ketamine users were categorized as adolescent-onset and adult-onset based on when they were first exposed to ketamine. Imaging data were processed by published routines in SPM and AFNI. The results revealed lower GMV in the left precuneus in ketamine users, with a larger decrease in the adolescent-onset group. The results from a seed-based correlation analysis show that both ketamine groups had higher functional connectivity between left precuneus (seed) and right precuneus than the control group. Compared to controls, ketamine users showed decreased GMV in the right insula, left inferior parietal lobule, left dorsolateral prefrontal cortex/superior frontal gyrus, and left medial orbitofrontal cortex. These preliminary results characterize the effects of ketamine misuse on brain structure and function and highlight the influence of earlier exposure to ketamine on the development of the brain. The precuneus, a structure of central importance to cerebral functional organization, may be particularly vulnerable to the influences of early ketamine exposure. How these structural and functional brain changes may relate to the cognitive and affective deficits remains to be determined with a large cohort of participants.

scholarly journals Computerized physical and cognitive training improves the functional architecture of the brain in adults with Down syndrome: A network science EEG study

2020 ◽  
pp. 1-21
Author(s):  
Alexandra Anagnostopoulou ◽  
Charis Styliadis ◽  
Panagiotis Kartsidis ◽  
Evangelia Romanopoulou ◽  
Vasiliki Zilidou ◽  
...  
Keyword(s):  
Down Syndrome ◽  
Functional Connectivity ◽  
Cognitive Training ◽  
Resting State ◽  
Network Architecture ◽  
Right Hemisphere ◽  
Random Network ◽  
Brain Activity ◽  
Hierarchical Organization ◽  
The Brain

Understanding the neuroplastic capacity of people with Down syndrome (PwDS) can potentially reveal the causal relationship between aberrant brain organization and phenotypic characteristics. We used resting-state EEG recordings to identify how a neuroplasticity-triggering training protocol relates to changes in the functional connectivity of the brain’s intrinsic cortical networks. Brain activity of 12 PwDS before and after a 10-week protocol of combined physical and cognitive training was statistically compared to quantify changes in directed functional connectivity in conjunction with psychosomatometric assessments. PwDS showed increased connectivity within the left hemisphere and from left-to-right hemisphere, as well as increased physical and cognitive performance. Our findings reveal a strong adaptive neuroplastic reorganization as a result of the training that leads to a less-random network with a more pronounced hierarchical organization. Our results go beyond previous findings by indicating a transition to a healthier, more efficient, and flexible network architecture, with improved integration and segregation abilities in the brain of PwDS. Resting-state electrophysiological brain activity is used here for the first time to display meaningful relationships to underlying Down syndrome processes and outcomes of importance in a translational inquiry. This trial is registered with ClinicalTrials.gov Identifier NCT04390321.

scholarly journals Survivors of SARS-CoV-2 Infection Show Neuropsychiatric Sequelae Measured by Surveys, Neurocognitive Testing, and Magnetic Resonance Imaging: Preliminary Results

2021 ◽  
Author(s):  
Laura M. Hack ◽  
Jacob Brawer ◽  
Megan Chesnut ◽  
Xue Zhang ◽  
Max Wintermark ◽  
...  
Keyword(s):  
Cognitive Impairment ◽  
Functional Connectivity ◽  
Brain Structure ◽  
Functional Neuroimaging ◽  
Structure And Function ◽  
Self Report ◽  
Neurocognitive Testing ◽  
Preliminary Results ◽  
Brain Structure And Function ◽  
And Function

AbstractA significant number of individuals experience physical, cognitive, and mental health symptoms in the months after acute infection with SARS-CoV-2, the virus that causes COVID-19. This study assessed depressive and anxious symptoms, cognition, and brain structure and function in participants with symptomatic COVID-19 confirmed by PCR testing (n=100) approximately three months following infection, leveraging self-report questionnaires, objective neurocognitive testing, and structural and functional neuroimaging data. Preliminary results demonstrated that over 1/5 of our cohort endorsed clinically significant depressive and/or anxious symptoms, and >40% of participants had cognitive impairment on objective testing across multiple domains, consistent with ‘brain-fog’. While depression and one domain of quality of life (physical functioning) were significantly different between hospitalized and non-hospitalized participants, anxiety, cognitive impairment, and most domains of functioning were not, suggesting that the severity of SARS-CoV-2 infection does not necessarily relate to the severity of neuropsychiatric outcomes and impaired functioning in the months after infection. Furthermore, we found that the majority of participants in a subset of our cohort who completed structural and functional neuroimaging (n=15) had smaller olfactory bulbs and sulci in conjunction with anosmia. We also showed that this subset of participants had dysfunction in attention network functional connectivity and ventromedial prefrontal cortex seed-based functional connectivity. These functional imaging dysfunctions have been observed previously in depression and correlated with levels of inflammation. Our results support and extend previous findings in the literature concerning the neuropsychiatric sequelae associated with long COVID. Ongoing data collection and analyses within this cohort will allow for a more comprehensive understanding of the longitudinal relationships between neuropsychiatric symptoms, neurocognitive performance, brain structure and function, and inflammatory and immune profiles.

scholarly journals Quantitative Analysis of Retinal Structure and Function in Two Chromosomally Altered Mouse Models of Down Syndrome

2020 ◽  
Vol 61 (5) ◽  
pp. 25
Author(s):  
Daniella B. Victorino ◽  
Jonah J. Scott-McKean ◽  
Mark W. Johnson ◽  
Alberto C. S. Costa
Keyword(s):  
Down Syndrome ◽  
Quantitative Analysis ◽  
Mouse Models ◽  
Structure And Function ◽  
Retinal Structure ◽  
And Function

scholarly journals Sex Differences in Brain Structures and Functional Connectivity among Patients with Bipolar I Disorder

2021 ◽  
Author(s):  
Ming-Yang Li ◽  
Shih-Jen Tsai ◽  
Albert C. Yang
Keyword(s):  
Bipolar Disorder ◽  
Sex Differences ◽  
Functional Connectivity ◽  
Brain Structures ◽  
Structure And Function ◽  
Angular Gyrus ◽  
Cingulate Gyrus ◽  
Bipolar I Disorder ◽  
Left Thalamus ◽  
And Function

Objectives: Studies have demonstrated that sex differences may play a crucial role in the alternations of brain structures in individuals with bipolar disorder, but findings are not consistent. The current study identified sex differences in brain structure and function among a large sample of individuals with bipolar I disorder (BD-I). Methods: Structural and functional magnetic resonance imaging datasets were acquired from 105 individuals with BD-I (36 men and 69 women) and 210 healthy adults (72 men and 138 women). A general linear regression model was used for voxel-wise analysis of grey matter (GM) and functional connectivity. Age, sex, diagnosis, and sex-by-diagnosis interaction were defined as predictors. Results: In GM, the left caudate (p < .001), left thalamus (p < .001), right caudate (p = .003), right thalamus (p < .001), left anterior cingulate gyrus (p = .015), and left middle/posterior cingulate gyrus (p = .022) exhibited sex-by-diagnosis interaction. Furthermore, by using these six brain regions as seeds, we observed sex-by-diagnosis interaction in the alteration of functional connectivity between the left thalamus and right angular gyrus (p = .019). Conclusions: Our data revealed a sex-by-diagnosis interaction associated with structure and function of the limbic system in individuals with BD-I. These findings may serve as reference for future studies on the pathophysiology of bipolar disorder.

scholarly journals Cytokines and schizophrenia revisited: a two-sample multi-marker Mendelian randomization approach

2019 ◽  
Author(s):  
Hongyan Ren ◽  
Yajing Meng ◽  
Yamin Zhang ◽  
Qiang Wang ◽  
Wei Deng ◽  
...  
Keyword(s):  
Brain Structure ◽  
Mendelian Randomization ◽  
Gray Matter Volume ◽  
Causal Link ◽  
Structure And Function ◽  
Underlying Structure ◽  
Level Data ◽  
Brain Structure And Function ◽  
And Function ◽  
Immune Changes

AbstractBackgroundSchizophrenia is a complex mental disorder with recent evidence suggesting a critical immune component underpinning its pathophysiology. Two-sample Mendelian randomization (MR) provided an opportunity to probe the immune changes in schizophrenia by harnessing the increasing availability of summary-level data from large GWAS consortia.ObjectiveTo map the extensive immune response of schizophrenia in terms of cytokines/chemokines and to explore the effect of cytokines induced by schizophrenia (SCZ-induced cytokines) on the brain structure and functionSources and methodsUsing the summary-level data generated from GWAS of schizophrenia, cytokines in the peripheral blood and imaging-derived phenotypes (IDPs), we performed two rounds of two-sample MR analysis; the identified cytokines from first round of analysis (schizophrenia => cytokines) were modeled for its underlying structure and subsequent clustering analysis further grouped SCZ-induced cytokines based on their genetic similarities. The multi-phenotype summary statistics of each cytokine module were then used as instrumental variables (IVs) for the second round of MR analysis to detect their effect on brain structure and function.ResultsThe first round of MR analysis identified nine cytokines, the highlight of which includes IL18 (OR = 1.292, P = 8.37 × 10−42) and TNFa (OR = 0.721, P = 7.33 × 10−6), to be causally associated with schizophrenia. These SCZ-induced cytokines could be clustered into three modules. The second round of MR analysis (cytokine module => IDPs) indicated that module B (SCGFb-IP10-CTACK-IL6) significantly increased the level of IDPs including IDP_T1_SIENAX_peripheral_grey_normalised_volume (β = 0.0453, P = 4.40×1010), IDP_dMRI_TBSS_MD_Posterior_corona_radiata_R (β= 0.0584, P = 8.89× 10−16) and IDP_dMRI_TBSS_MD_Cingulum_hippocampus_R (β = 0.0563, P = 9.88× 10−15), with module C (IL18-GROa-TNFa) increasing the level of IDP_dMRI_TBSS_L2_Posterior_thalamic_radiation_R (β= 0.0341, P = 2.67× 10−6).ConclusionOur study, for the first time, mapped the causal link from schizophrenia to the comprehensive immune responses, and the findings suggest immune networks play a role in pathophysiology of schizophrenia by mediating the deviations of total gray matter volume and white matter fibers possibly in the mesolimbic system.

scholarly journals Neurological Soft Signs Predict Auditory Verbal Hallucinations in Patients With Schizophrenia

2020 ◽  
Author(s):  
Robert C Wolf ◽  
Mahmoud Rashidi ◽  
Mike M Schmitgen ◽  
Stefan Fritze ◽  
Fabio Sambataro ◽  
...  
Keyword(s):  
Neural Activity ◽  
Rating Scale ◽  
Gray Matter Volume ◽  
Structure And Function ◽  
Symptom Expression ◽  
Binary Logistic Regression Model ◽  
Neurological Soft Signs ◽  
Specific Symptom ◽  
Auditory Verbal Hallucinations ◽  
And Function

Abstract Neurological soft signs (NSS) are well documented in individuals with schizophrenia (SZ), yet so far, the relationship between NSS and specific symptom expression is unclear. We studied 76 SZ patients using magnetic resonance imaging (MRI) to determine associations between NSS, positive symptoms, gray matter volume (GMV), and neural activity at rest. SZ patients were hypothesis-driven stratified according to the presence or absence of auditory verbal hallucinations (AVH; n = 34 without vs 42 with AVH) according to the Brief Psychiatric Rating Scale. Structural MRI data were analyzed using voxel-based morphometry, whereas intrinsic neural activity was investigated using regional homogeneity (ReHo) measures. Using ANCOVA, AVH patients showed significantly higher NSS in motor and integrative functions (IF) compared with non-hallucinating (nAVH) patients. Partial correlation revealed that NSS IF were positively associated with AVH symptom severity in AVH patients. Such associations were not confirmed for delusions. In region-of-interest ANCOVAs comprising the left middle and superior temporal gyri, right paracentral lobule, and right inferior parietal lobule (IPL) structure and function, significant differences between AVH and nAVH subgroups were not detected. In a binary logistic regression model, IF scores and right IPL ReHo were significant predictors of AVH. These data suggest significant interrelationships between sensorimotor integration abilities, brain structure and function, and AVH symptom expression.

Sign in / Sign up

Export Citation Format

Share Document