scholarly journals Aberrant Structural and Functional Developmental Trajectories in Children With Intellectual Disability

2021 ◽  
Vol 12 ◽  
Author(s):  
Xuejin Ma ◽  
Jianxia Tan ◽  
Lin Jiang ◽  
Xuqin Wang ◽  
Bochao Cheng ◽  
...  
Keyword(s):  
Intellectual Disability ◽  
Functional Connectivity ◽  
Developmental Trajectories ◽  
Structure And Function ◽  
Anterior Cingulate ◽  
Matter Volume ◽  
Functional Development ◽  
Iq Scores ◽  
And Function ◽  
The Brain

Intellectual disability (ID) is associated with aberrant structural and functional development of the brain, yet how the dynamical developmental changes of the structure and function of ID from childhood to around puberty remains unknown. To explore the abnormal developmental trajectories of structure and function, 40 children with ID aged 6–13 years and 30 sex-, age-, and educational level-matched healthy controls (HC) with age range from 6 to 13 were recruited. The automatic voxel-based morphometry (VBM) and resting-state functional connectivity (FC) analyses were adopted to delineate the structural and functional differences. Significantly decreased total gray matter volume (GMV) and white matter volume (WMV) in children with ID were found, and the developmental trajectories of GMV and WMV in children with ID showed an opposite direction as compared with HC. The voxel-wise VMB analysis further revealed significantly increased GMV in the dorsal medial prefrontal cortex (dmPFC), bilateral orbital part of the inferior frontal gyrus (orb_IFG.L, orb_IFG.R), right cuneus (cuneus.R), and bilateral middle frontal gyrus (MFG.L, MFG.R) in children with ID. The following seed-based whole-brain functional connectivity analyses of the brain areas with changed GMV found decreased FCs between the cuneus.R and left intraparietal sulcus (IPS.L) and between the MFG.R and anterior cingulate cortex (ACC) in children with ID. Moreover, negative correlations between GMV values in the dmPFC, orb_IFG.L, cuneus.R, and intelligence quotient (IQ) scores and positive correlations between the FCs of the cuneus.R with IPS.L and MFG.R with ACC and IQ scores were found in children with ID and HC. Our findings provide evidence for the abnormal structural and functional development in children with ID and highlight the important role of frontoparietal network in the typical development. The abnormal development of GMV and functional couplings found in this study may be the neuropathological bases of children with ID.

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 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 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.

The role of GABAA receptor biogenesis, structure and function in epilepsy

2006 ◽  
Vol 34 (5) ◽  
pp. 863-867 ◽  
Author(s):  
S. Mizielinska ◽  
S. Greenwood ◽  
C.N. Connolly
Keyword(s):  
Gabaa Receptor ◽  
Structure And Function ◽  
Inhibitory Synapses ◽  
Normal Brain ◽  
Synaptic Targeting ◽  
Acid Type ◽  
Normal Brain Function ◽  
And Function ◽  
The Brain

Maintaining the correct balance in neuronal activation is of paramount importance to normal brain function. Imbalances due to changes in excitation or inhibition can lead to a variety of disorders ranging from the clinically extreme (e.g. epilepsy) to the more subtle (e.g. anxiety). In the brain, the most common inhibitory synapses are regulated by GABAA (γ-aminobutyric acid type A) receptors, a role commensurate with their importance as therapeutic targets. Remarkably, we still know relatively little about GABAA receptor biogenesis. Receptors are constructed as pentameric ion channels, with α and β subunits being the minimal requirement, and the incorporation of a γ subunit being necessary for benzodiazepine modulation and synaptic targeting. Insights have been provided by the discovery of several specific assembly signals within different GABAA receptor subunits. Moreover, a number of recent studies on GABAA receptor mutations associated with epilepsy have further enhanced our understanding of GABAA receptor biogenesis, structure and function.

Normal ageing and the brain

1998 ◽  
Vol 15 (1) ◽  
pp. 26-28
Author(s):  
CS Breathnach
Keyword(s):  
Cerebral Cortex ◽  
Imaging Techniques ◽  
Structure And Function ◽  
Ageing Population ◽  
Cell Shrinkage ◽  
Ageing Processes ◽  
Normal Ageing ◽  
And Function ◽  
Ageing Brain ◽  
The Brain

AbstractInterest in the psychiatric aspects of old age predated the institution of geriatrics as a clinical discipline, but the systematic study of the ageing brain only began in the second half of this century when an ageing population presented a global numerical challenge to society. In the senescent cerebral cortex, though the number of neurons is not reduced, cell shrinkage results in synaptic impoverishment with consequent cognitive impairment. Recent advances in imaging techniques, combined with burgeoning knowledge of neurobiological structure and function, have increased our understanding of the ageing processes in the human brain and permit an optimistic approach in the application of the newer insights into neuropsychology and geriatric psychiatry.

scholarly journals Culture Wires the Brain

2010 ◽  
Vol 5 (4) ◽  
pp. 391-400 ◽  
Author(s):  
Denise C. Park ◽  
Chih-Mao Huang
Keyword(s):  
Brain Structure ◽  
Cultural Psychology ◽  
Structure And Function ◽  
Neural Function ◽  
Limited Evidence ◽  
Neural Structure ◽  
Cultural Experiences ◽  
Brain Structure And Function ◽  
And Function ◽  
The Brain

There is clear evidence that sustained experiences may affect both brain structure and function. Thus, it is quite reasonable to posit that sustained exposure to a set of cultural experiences and behavioral practices will affect neural structure and function. The burgeoning field of cultural psychology has often demonstrated the subtle differences in the way individuals process information—differences that appear to be a product of cultural experiences. We review evidence that the collectivistic and individualistic biases of East Asian and Western cultures, respectively, affect neural structure and function. We conclude that there is limited evidence that cultural experiences affect brain structure and considerably more evidence that neural function is affected by culture, particularly activations in ventral visual cortex—areas associated with perceptual processing.

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.

Mental illness: The collision of meaning with mechanism

2020 ◽  
pp. 263-289
Author(s):  
Steven E. Hyman ◽  
Doug McConnell
Keyword(s):  
Mental Illness ◽  
Gene Regulation ◽  
Human Brain ◽  
Lived Experience ◽  
Clinical Encounter ◽  
Structure And Function ◽  
Human Beings ◽  
And Function ◽  
Human Brains ◽  
The Brain

‘Mental illness: the collision of meaning with mechanism’ is based on the views of psychiatry that Steven Hyman articulated in his Loebel Lectures—mental illness results from the disordered functioning of the human brain and effective treatment repairs or mitigates those malfunctions. This view is not intended as reductionist as causes of mental illness and contributions to their repair may come from any source that affects the structure and function of the brain. These might include social interactions and other sources of lived experience, ideas (such as those learned in cognitive therapy), gene sequences and gene regulation, metabolic factors, drugs, electrodes, and so on. This, however, is not the whole story for psychiatry on Hyman’s view; interpersonal interactions between clinicians and patients, intuitively understood in such folk psychological terms as selfhood, intention, and agency are also critical for successful practice. As human beings who are suffering, patients seek to make sense of their lives and benefit from the empathy, respect, and a sense of being understood not only as the objects of a clinical encounter, but also as subjects. Hyman’s argument, however, is that the mechanisms by which human brains function and malfunction to produce the symptoms and impairments of mental illness are opaque to introspection and that the mechanistic understandings necessary for diagnosis and treatment are incommensurate with intuitive (folk psychological) human self-understanding. Thus, psychiatry does best when skillful clinicians switch between an objectifying medical and neurobiological stance and the interpersonal stance in which the clinician engages the patients as a subject. Attempts to integrate these incommensurate views of patients and their predicaments have historically produced incoherent explanations of psychopathology and have often led treatment astray. For example, privileging of folk psychological testimony, even when filtered through sophisticated theories has historically led psychiatry into intellectually blind and clinically ineffective cul-de-sacs such as psychoanalysis.

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