Attention and regional gray matter development in very preterm children at age 12 years

Objectives: This study examines the selective, sustained, and executive attention abilities of very preterm (VPT) born children in relation to concurrent structural magnetic resonance imaging (MRI) measures of regional gray matter development at age 12 years. Methods: A regional cohort of 110 VPT (≤32 weeks gestation) and 113 full term (FT) born children were assessed at corrected age 12 years on the Test of Everyday Attention-Children. They also had a structural MRI scan that was subsequently analyzed using voxel-based morphometry to quantify regional between-group differences in cerebral gray matter development, which were then related to attention measures using multivariate methods. Results: VPT children obtained similar selective (p=.85), but poorer sustained (p=.02) and executive attention (p=.01) scores than FT children. VPT children were also characterized by reduced gray matter in the bilateral parietal, temporal, prefrontal and posterior cingulate cortices, bilateral thalami, and left hippocampus; and increased gray matter in the occipital and anterior cingulate cortices (family-wise error-corrected

Association of Superoxide Dismutase 2 (SOD2) Genotype with Gray Matter Volume Shrinkage in Chronic Alcohol Users: Replication and Further Evaluation of an Addiction Gene Panel.

BackgroundReduction in brain volume, especially gray matter volume, has been shown to be one of the many deleterious effects of prolonged alcohol consumption. High variance in the degree of gray matter tissue shrinkage among alcohol-dependent individuals and a previous neuroimaging genetics report suggest the involvement of environmental and/or genetic factors, such as superoxide dismutase 2 (SOD2). Identification of such underlying factors will help in the clinical management of alcohol dependence.MethodsWe analyzed quantitative magnetic resonance imaging and genotype data from 103 alcohol users, including both light drinkers and treatment-seeking alcohol-dependent individuals. Genotyping was performed using a custom gene array that included genes selected from 8 pathways relevant to chronic alcohol-related brain volume loss.ResultsWe replicated a significant association of a functional SOD2 single nucleotide polymorphism with normalized gray matter volume, which had been reported previously in an independent smaller sample of alcohol-dependent individuals. The SOD2-related genetic protection was observed only at the cohort's lower drinking range. Additional associations between normalized gray matter volume and other candidate genes such as alcohol dehydrogenase gene cluster (ADH), GCLC, NOS3, and SYT1 were observed across the entire sample but did not survive corrections for multiple comparisons.ConclusionConverging independent evidence for a SOD2 gene association with gray matter volume shrinkage in chronic alcohol users suggests that SOD2 genetic variants predict differential brain volume loss mediated by free radicals. This study also provides the first catalog of genetic variations relevant to gray matter loss in chronic alcohol users. The identified gene-brain structure relationships are functionally pertinent and merit replication

Brainstem atrophy in focal epilepsy destabilizes brainstem-brain interactions: Preliminary findings.

BACKGROUND: MR Imaging has shown atrophy in brainstem regions that were linked to autonomic dysfunction in epilepsy patients. The brainstem projects to and modulates the activation state of several wide-spread cortical/subcortical regions. The goal was to investigate 1. Impact of brainstem atrophy on gray matter connectivity of cortical/subcortical structures and autonomic control. 2. Impact on the modulation of cortical/subcortical functional connectivity. METHODS: 11 controls and 18 patients with non-lesional focal epilepsy (FE) underwent heart rate variability (HRV) measurements and a 3 T MRI (T1 in all subjects, task-free fMRI in 7 controls/ 12 FE). The brainstem was extracted, and atrophy assessed using deformation-based-morphometry. The age-corrected z-scores of the mean Jacobian determinants were extracted from 71 5x5x5 mm grids placed in brainstem regions associated with autonomic function. Cortical and non-brainstem subcortical gray matter atrophy was assessed with voxel-based-morphometry and mean age corrected z-scores of the modulated gray matter volumes extracted from 380 cortical/subcortical rois. The profile similarity index was used to characterize the impact of brainstem atrophy on gray matter connectivity. The fMRI was preprocessed in SPM12/Conn17 and the BOLD signal extracted from 398 ROIs (16 brainstem). A dynamic task-free analysis approach was used to identify activation states. Connectivity HRV relationship were assessed with Spearman rank correlations. RESULTS: HRV was negatively correlated with reduced brainstem right hippocampus/parahippocampus gray matter connectivity in controls (p \u3c .05, FDR) and reduced brainstem to right parietal cortex, lingual gyrus, left hippocampus/amygdala, parahippocampus, temporal pole, and bilateral anterior thalamus connectivity in FE (p \u3c .05, FDR). Dynamic task-free fMRI analysis identified 22 states. The strength of the functional brainstem/cortical connectivity of state 15 was negatively associated with HRV (r = -0.5, p = .03) and positively with decreased brainstem-cortical (0.49, p = .03) gray matter connectivity. CONCLUSION: The findings of this small pilot study suggest that impaired brainstem-cortex gray matter connectivity in FE negatively affects the brainstem\u27s ability to control cortical activation

Gray-matter volume, midbrain dopamine D2/D3 receptors and drug craving in methamphetamine users.

Dysfunction of the mesocorticolimbic system has a critical role in clinical features of addiction. Despite evidence suggesting that midbrain dopamine receptors influence amphetamine-induced dopamine release and that dopamine is involved in methamphetamine-induced neurotoxicity, associations between dopamine receptors and gray-matter volume have been unexplored in methamphetamine users. Here we used magnetic resonance imaging and [(18)F]fallypride positron emission tomography, respectively, to measure gray-matter volume (in 58 methamphetamine users) and dopamine D2/D3 receptor availability (binding potential relative to nondisplaceable uptake of the radiotracer, BPnd) (in 31 methamphetamine users and 37 control participants). Relationships between these measures and self-reported drug craving were examined. Although no difference in midbrain D2/D3 BPnd was detected between methamphetamine and control groups, midbrain D2/D3 BPnd was positively correlated with gray-matter volume in the striatum, prefrontal cortex, insula, hippocampus and temporal cortex in methamphetamine users, but not in control participants (group-by-midbrain D2/D3 BPnd interaction, P<0.05 corrected for multiple comparisons). Craving for methamphetamine was negatively associated with gray-matter volume in the insula, prefrontal cortex, amygdala, temporal cortex, occipital cortex, cerebellum and thalamus (P<0.05 corrected for multiple comparisons). A relationship between midbrain D2/D3 BPnd and methamphetamine craving was not detected. Lower midbrain D2/D3 BPnd may increase vulnerability to deficits in gray-matter volume in mesocorticolimbic circuitry in methamphetamine users, possibly reflecting greater dopamine-induced toxicity. Identifying factors that influence prefrontal and limbic volume, such as midbrain BPnd, may be important for understanding the basis of drug craving, a key factor in the maintenance of substance-use disorders

Isointense infant brain MRI segmentation with a dilated convolutional neural network

Quantitative analysis of brain MRI at the age of 6 months is difficult because of the limited contrast between white matter and gray matter. In this study, we use a dilated triplanar convolutional neural network in combination with a non-dilated 3D convolutional neural network for the segmentation of white matter, gray matter and cerebrospinal fluid in infant brain MR images, as provided by the MICCAI grand challenge on 6-month infant brain MRI segmentation.Comment: MICCAI grand challenge on 6-month infant brain MRI segmentatio

Uncovering the Social Deficits in the Autistic Brain. A Source-Based Morphometric Study

Autism is a neurodevelopmental disorder that mainly affects social interaction and communication. Evidence from behavioral and functional MRI studies supports the hypothesis that dysfunctional mechanisms involving social brain structures play a major role in autistic symptomatology. However, the investigation of anatomical abnormalities in the brain of people with autism has led to inconsistent results. We investigated whether specific brain regions, known to display functional abnormalities in autism, may exhibit mutual and peculiar patterns of covariance in their gray-matter concentrations. We analyzed structural MRI images of 32 young men affected by autistic disorder (AD) and 50 healthy controls. Controls were matched for sex, age, handedness. IQ scores were also monitored to avoid confounding. A multivariate Source-Based Morphometry (SBM) was applied for the first time on AD and controls to detect maximally independent networks of gray matter. Group comparison revealed a gray-matter source that showed differences in AD compared to controls. This network includes broad temporal regions involved in social cognition and high-level visual processing, but also motor and executive areas of the frontal lobe. Notably, we found that gray matter differences, as reflected by SBM, significantly correlated with social and behavioral deficits displayed by AD individuals and encoded via the Autism Diagnostic Observation Schedule scores. These findings provide support for current hypotheses about the neural basis of atypical social and mental states information processing in autism

Regional gray matter correlates of vocational interests.

BackgroundPrevious studies have identified brain areas related to cognitive abilities and personality, respectively. In this exploratory study, we extend the application of modern neuroimaging techniques to another area of individual differences, vocational interests, and relate the results to an earlier study of cognitive abilities salient for vocations.FindingsFirst, we examined the psychometric relationships between vocational interests and abilities in a large sample. The primary relationships between those domains were between Investigative (scientific) interests and general intelligence and between Realistic ("blue-collar") interests and spatial ability. Then, using MRI and voxel-based morphometry, we investigated the relationships between regional gray matter volume and vocational interests. Specific clusters of gray matter were found to be correlated with Investigative and Realistic interests. Overlap analyses indicated some common brain areas between the correlates of Investigative interests and general intelligence and between the correlates of Realistic interests and spatial ability.ConclusionsTwo of six vocational-interest scales show substantial relationships with regional gray matter volume. The overlap between the brain correlates of these scales and cognitive-ability factors suggest there are relationships between individual differences in brain structure and vocations

Striatal dopamine D1-type receptor availability: no difference from control but association with cortical thickness in methamphetamine users.

Chronic methamphetamine use poses potentially devastating consequences for directly affected individuals and for society. Lower dopamine D2-type receptor availability has been observed in striata of methamphetamine users as compared with controls, but an analogous comparison of D1-type receptors has been conducted only on post-mortem material, with no differences in methamphetamine users from controls in the caudate nucleus and putamen and higher D1-receptor density in the nucleus accumbens. Released from neurons when methamphetamine is self-administered, dopamine binds to both D1- and D2-type receptors in the striatum, with downstream effects on cortical activity. Thus, both receptor subtypes may contribute to methamphetamine-induced alterations in cortical morphology and behavior. In this study, 21 methamphetamine-dependent subjects and 23 healthy controls participated in positron emission tomography and structural magnetic resonance imaging for assessment of striatal D1- and D2-type receptor availability and cortical gray-matter thickness, respectively. Although D2-type receptor availability (BPnd) was lower in the methamphetamine group, as shown previously, the groups did not differ in D1-type BPnd. In the methamphetamine group, mean cortical gray-matter thickness was negatively associated with cumulative methamphetamine use and craving for the drug. Striatal D1-type but not D2-type BPnd was negatively associated with global mean cortical gray-matter thickness in the methamphetamine group, but no association was found between gray-matter thickness and BPnd for either dopamine receptor subtype in the control group. These results suggest a role of striatal D1-type receptors in cortical adaptation to chronic methamphetamine use

Deep and cortical gray matter volumetric of extremely low gestational age and full term newborn children at 9 to 11 years of age

PURPOSE: Extremely low gestation age newborns (ELGANs) are at high risk for developmental brain abnormalities. This study is to determine deep and superficial gray matter volumetric abnormalities of ELGAN children and full term children at 9 to 11 years of age. METHODS: High-resolution magnetic resonance imaging (MRI) scans were obtained from 160 ELGAN children (70 males and 90 females) and 30 full term children (15 males and 15 females) using a dual-echo turbo spin-echo (DE-TSE) pulse sequence at 3.0T (or 1.5T at only one site). The DICOM MR images were processed with quantitative MRI algorithms programmed in Mathcad. The brain deep gray matter (dGM) was manually segmented; dGM and cortical gray matter (cGM) volumes were quantified using semi-automated clustering segmentation algorithms. RESULTS: ELGAN children had smaller deep gray matter volume (41.86 ± 7.42 ml) than full term children (49.24 ± 10.91 ml). Deep gray matter volumes of ELGAN children showed similar distribution range (SD = 7.42 ml) with the full term children (SD = 10.91 ml). About 83% of the ELGAN children had smaller deep gray matter volumes compared to the average volume of full term children at the same ages. Male children had smaller deep gray matter volumes in ELGAN (42.77 ± 7.09 ml) than in full term (51.74 ± 9.76 ml), but female children had similar deep gray matter volumes in ELGAN (41.14 ± 7.62 ml) with full term (44.27 ± 7.56 ml). Additionally, smaller deep gray matter volumes were observed more often in males (90%) than in females (65%). Cortical gray matter volumes of ELGAN children distributed from 345.60 to 1177.50ml. Moreover, female ELGAN children had smaller cortical gray matter volumes (828.14 ± 147.61 ml) than males (883.13 ± 151.34 ml). Correlation analysis revealed a positive correlation between cerebral deep gray matter volumes and total gray matter volumes (total: r = 0.57, p<0.0001; male: r = 0.542, p < 0.0001; female: r = 0.587, p < 0.0001). CONCLUSION: Male ELGAN children had smaller brain deep gray matter volumes than full term children at ages of 9 to 11 years, but not females. Cortical gray matter volumes of female ELGAN were smaller than male ELGAN. Smaller deep gray matter volumes were associated with smaller total gray matter volumes in ELGAN children