Differences In Brain Morphology Research Articles

The Influence of Genome and Cell Size on Brain Morphology in Amphibians.

In amphibians, nerve cell size is highly correlated with genome size, and increases in genome and cell size cause a retardation of the rate of development of nervous (as well as nonnervous) tissue leading to secondary simplification. This yields an inverse relationship between genome and cell size on the one hand and morphological complexity of the tectum mesencephali as the main visual center, the size of the torus semicircularis as the main auditory center, the size of the amphibian papilla as an important peripheral auditory structure, and the size of the cerebellum as a major sensorimotor center. Nervous structures developing later (e.g., torus and cerebellum) are more affected by secondary simplification than those that develop earlier (e.g., the tectum). This effect is more prominent in salamanders and caecilians than in frogs owing to larger genome and cells sizes in the former two taxa. We hypothesize that because of intragenomic evolutionary processes, important differences in brain morphology can arise independently of specific environmental selection.

Brain volume and white matter in youth with type 2 diabetes compared to obese and normal weight, non-diabetic peers: A pilot study

Type 2 Diabetes Mellitus (T2DM) and obesity are linked to specific patterns of subcortical brain atrophy and decreased microstructural integrity of white matter. Fifteen adolescents (12–21-years-old, 80% Caucasian, 15% African American, mean BMI=32)–five with T2DM confirmed by oral glucose tolerance test, five matched obese adolescent controls without diabetes (OBCN), and five matched (race, sex) normal-weight controls (NWCN)–underwent Magnetic Resonance Imaging (MRI) for the collection of gray matter volume and white matter integrity. Analyses of Variance (ANOVAs) of the neuroimaging data revealed significant differences in caudate nucleus volume [F(2,12)=7.79, p<0.05] such that the normal-weight group had significantly greater volume than the obese and T2DM groups (NWCN>OBCN, p=0.020; OBCN>T2DM, p=0.042; and NWCN>T2DM; p=0.003) after controlling for participant Body Mass Index (BMI). Similarly, there was a main effect for the volume of the thalamus [F(2,12)=4.39, p<0.05] with greater volume for both the NWC and the OBC groups in comparison to the T2DM group (NWC>T2DM, p=0.020; OBC>T2DM; p=0.040). Finally, an examination of white matter integrity among the three groups illustrated a pattern of white matter integrity reduction between normal-weight participants and both obese controls and T2DM participants, with T2DM demonstrating the greatest deficit in functional anisotropy (FA) volume, but these results were not significant after further controlling for BMI. Results from the current pilot study illuminate a host of brain morphology differences between youth with T2DM, obese youth, and normal-weight controls; future research with a larger sample size is critical.

Structural brain aberrations associated with the dissociative subtype of post-traumatic stress disorder.

One factor potentially contributing to the heterogeneity of previous results on structural grey matter alterations in adult participants suffering from post-traumatic stress disorder (PTSD) is the varying levels of dissociative symptomatology. The aim of this study was therefore to test whether the recently defined dissociative subtype of PTSD characterized by symptoms of depersonalization and derealization is characterized by specific differences in volumetric brain morphology. Whole-brain MRI data were acquired for 59 patients with PTSD. Voxel-based morphometry was carried out to test for group differences between patients classified as belonging (n = 15) vs. not belonging (n = 44) to the dissociative subtype of PTSD. The correlation between dissociation (depersonalization/derealization) severity and grey matter volume was computed. Patients with PTSD classified as belonging to the dissociative subtype exhibited greater grey matter volume in the right precentral and fusiform gyri as well as less volume in the right inferior temporal gyrus. Greater dissociation severity was associated with greater volume in the right middle frontal gyrus. The results of this first whole-brain investigation of specific grey matter volume in dissociative subtype PTSD indentified structural aberrations in regions subserving the processing and regulation of emotional arousal. These might constitute characteristic biomarkers for the dissociative subtype PTSD.

Key Identifiers of Pedophilia and Differences in Pedophile Brain Morphology: A Comparative Approach

Key Identifiers of Pedophilia and Differences in Pedophile Brain Morphology: A Comparative Approach

Brain morphology in juvenile myoclonic epilepsy and absence seizures.

We evaluated the differences in brain morphology among patients with juvenile myoclonic epilepsy according to the occurrence of absence seizures. Twenty-one juvenile myoclonic epilepsy patients with (n=6) and without (n=15) absence seizures were enrolled. We analyzed whole-brain T1-weighted magnetic resonance imaging using FreeSurfer 5.1. Measures of cortical morphology, such as thickness, surface area, volume, and curvature, and the volumes of subcortical structures, the cerebellum, and cerebrum, were compared between the groups. Moreover, we quantified correlations between clinical variables and each measures of abnormal brain morphology. Compared to normal controls, patients without absence seizures demonstrated thinning of the cortical thickness in the right hemisphere, including the post-central, lingual, orbitofrontal, and lateral occipital cortex. Compared to normal controls, patients with absence seizures had more widespread thinning of the cortical thickness, including the right post-central, lingual, orbitofrontal, and lateral occipital cortexes as well as the right inferior temporal cortex. Additionally, the volume of cerebellar white matter in patients without absence seizures was significantly smaller than that in normal controls. Patients with absence seizures had a much smaller cerebellar white matter volume than normal controls or patients without absence seizures. Moreover, there was significantly positive correlation between the age of seizure onset and the volume of cerebellar white matter in patients with juvenile myoclonic epilepsy. We demonstrated that there were significant brain morphology differences in patients with juvenile myoclonic epilepsy according to the presence of absence seizures. These findings support the hypothesis that juvenile myoclonic epilepsy may be a heterogeneous syndrome.

Brain morphology is individual-specific information

The identification of individual differences in brain morphology is important to understand the background of individual differences in brain functions. In the present study, we investigated whether brain morphology is discernibly different among individuals and is personally identifiable information. Using structural magnetic resonance imaging data from 215 healthy subjects scanned twice (scan interval = 1.0 ± 0.1 years), we performed brain recognition by image normalization using a voxel-based morphometry approach, feature extraction based on principal component analysis, and calculating the Euclidean distances between image pairs projected into the subspace. Even with only 32 dimensions used for projection, the rank-one identification rate was 99.5%. With ≥112 dimensions used, the rank-one identification rate was 100%. At a false accept rate of 0.01%, the genuine accept rates were 95.8% and 100% with 32 and ≥128 dimensions used for projection, respectively. There was little difference in the Euclidean distances among different combinations of scanners used or between probe–gallery image pairs with and without scanner upgrade. These results indicate that brain morphology can identify a specific individual; i.e., brain morphology is personally identifiable information. Individually different brain morphology may occur as a collection of differences in brain structures that reflect individual differences in a variety of performances and various psychological characteristics and behavior patterns, and may provide the background of individual differences in personality and brain function.

Autistic disorder and cancer risk

Autism and neuropsychiatric disorders have been linked to an increasing number of genes, some developmental and others cancer predisposition loci. Autism also has been related to abnormal neural development with macrocephaly and differences in brain morphology. Thus, it is natural to consider whether autism and cancer might share a common link because of dys-regulation of loss of growth. Chiang et al approach this topic with their Taiwanese national cohort study examining 8,438 children diagnosed with cancer from 1997 to 2011. Cancer developed nearly twice as often as suspected in children with autistic disorder, with a standardized incidence ratio of 1.94 (95% CI 1.18-2.99). Although these data are significant, we should exercise caution when interpreting their results. The study findings are based upon 20 individuals diagnosed with cancer, when only about 10 were expected. Although the study sample here is larger than prior works, the number of children with overlapping autistic disorder and cancer remains small. Children with autistic disorder overwhelmingly still did not develop cancer. More work is needed to explore the biological underpinnings of this relationship. Article page 418▶ Risk of Cancer in Children, Adolescents, and Young Adults with Autistic DisorderThe Journal of PediatricsVol. 166Issue 2PreviewTo investigate whether individuals with autism have an increased risk for cancer relative to the general population. Full-Text PDF

Seizure expression, behavior, and brain morphology differences in colonies of Genetic Absence Epilepsy Rats from Strasbourg.

Originally derived from a Wistar rat strain, a proportion of which displayed spontaneous absence-type seizures, Genetic Absence Epilepsy Rats from Strasbourg (GAERS) represent the most widely utilized animal model of genetic generalized epilepsy. Here we compare the seizure, behavioral, and brain morphometric characteristics of four main GAERS colonies that are being actively studied internationally: two from Melbourne (MELB and STRAS-MELB), one from Grenoble (GREN), and one from Istanbul (ISTAN). Electroencephalography (EEG) recordings, behavioral examinations, and structural magnetic resonance imaging (MRI) studies were conducted on GAERS and Non-Epileptic Control (NEC) rats to assess and compare the following: (1) characteristics of spike-and-wave discharges, (2) anxiety-like and depressive-like behaviors, and (3) MRI brain morphology of regions of interest. Seizure characteristics varied between the colonies, with MELB GAERS exhibiting the least severe epilepsy phenotype with respect to seizure frequency, and GREN GAERS exhibiting four times more seizures than MELB. MELB and STRAS-MELB colonies both displayed consistent anxiety and depressive-like behaviors relative to NEC. MELB and GREN GAERS showed similar changes in brain morphology, including increased whole brain volume and increased somatosensory cortical width. A previously identified mutation in the Cacna1h gene controlling the CaV 3.2 T-type calcium channel (R1584P) was present in all four GAERS colonies, but absent in all NEC rats. This study demonstrates differences in epilepsy severity between GAERS colonies that were derived from the same original colony in Strasbourg. This multi-institute study highlights the potential impact of environmental conditions and/or genetic drift on the severity of epileptic and behavioral phenotypes in rodent models of epilepsy.

The domestic piglet: an important model for investigating the neurodevelopmental consequences of early life insults.

Insults in the prenatal and early postnatal period increase the risk for behavioral problems later in life. One hypothesis is that pre- and postnatal stressors influence structural and functional brain plasticity. Understanding the mechanisms is important, but progress has lagged because certain studies in human infants are impossible, while others are extremely difficult. Furthermore, results from popular rodent models are difficult to translate to human infants owing to the substantial differences in brain development and morphology. Because it overcomes some of these obstacles, the domestic piglet has emerged as an important model. Piglets have a gyrencephalic brain that develops similar to the human brain and that can be assessed in vivo by using clinical-grade neuroimaging instruments. Furthermore, owing to their precocial nature, piglets can be weaned at birth and used in behavioral testing paradigms to assess cognitive behavior at an early age. Thus, the domestic piglet represents an important translational model for investigating the neurodevelopmental consequences of early life insults.

Associations between brain morphology and outcome in schizophrenia in a general population sample

To analyse associations between brain morphology and longitudinal and cross-sectional measures of outcomes in schizophrenia in a general population sample. The sample was the Northern Finland 1966 Birth Cohort. In 1999-2001, structural brain MRI and measures of clinical and functional outcomes were analysed for 54 individuals with schizophrenia around the age of 34. Sex, total grey matter, duration of illness and the use of antipsychotic medication were used as covariates. After controlling for multiple covariates, increased density of the left limbic area was associated with less hospitalisations and increased total white matter volume with being in remission. Higher density of left frontal grey matter was associated with not being on a disability pension and higher density of the left frontal lobe and left limbic area were related to better functioning. Higher density of the left limbic area was associated with better longitudinal course of illness. This study, based on unselected general population data, long follow-up and an extensive database, confirms findings of previous studies, that morphological abnormalities in several brain structures are associated with outcome. The difference in brain morphology in patients with good and poor outcomes may reflect separable aetiologies and developmental trajectories in schizophrenia.

Moderate alcohol exposure during early brain development increases stimulus‐response habits in adulthood

Exposure to alcohol during early central nervous system development has been shown variously to affect aspects of physiological and behavioural development. In extreme cases, this can extend to craniofacial defects, severe developmental delay and mental retardation. At more moderate levels, subtle differences in brain morphology and behaviour have been observed. One clear effect of developmental alcohol exposure is an increase in the propensity to develop alcoholism and other addictions. The mechanisms by which this occurs, however, are not currently understood. In this study, we tested the hypothesis that adult zebrafish chronically exposed to moderate levels of ethanol during early brain ontogenesis would show an increase in conditioned place preference for alcohol and an increased propensity towards habit formation, a key component of drug addiction in humans. We found support for both of these hypotheses and found that the exposed fish had changes in mRNA expression patterns for dopamine receptor, nicotinic acetylcholine receptor and μ-opioid receptor encoding genes. Collectively, these data show an explicit link between the increased proclivity for addiction and addiction-related behaviour following exposure to ethanol during early brain development and alterations in the neural circuits underlying habit learning.

Time of acquisition and network stability in pediatric resting-state functional magnetic resonance imaging.

Resting-state functional magnetic resonance imaging (rs-fMRI) has been shown to elucidate reliable patterns of brain networks in both children and adults. Studies in adults have shown that rs-fMRI acquisition times of ∼5 to 6 min provide adequate sampling to produce stable spatial maps of a number of different brain networks. However, it is unclear whether the acquisition time directly translates to studies of children. While there are many similarities between the brains of children and adults, many differences are also evident. Children have increased metabolism, differences in brain morphology and connectivity strengths, greater brain plasticity, and increased brain noise. Furthermore, there are differences in physiologic parameters, such as heart and respiratory rates, and compliance of the blood vessels. These developmental differences could translate into different acquisition times for rs-fMRI studies in pediatric populations. Longer scan times, however, increase the subject burden and the risk for greater movement, especially in children. Thus, the goal of this study was to assess the optimum acquisition time of rs-fMRI to extract stable brain networks in school-age children. We utilized fuzzy set theory in 84 six-to-eight year-old children and found that eight networks, including the default mode, salience, frontal, left frontoparietal, right frontoparietal, sensorimotor, auditory, and visual networks, all stabilized after ∼5½ min. The sensorimotor network showed the least stability, whereas the salience and auditory networks showed the greatest stability. A secondary analysis using dual regression confirmed these results. In conclusion, in young children with little head motion, rs-fMRI acquisition times of ∼5½ min can extract the full complement of brain networks.

Overlapping trisomies for human chromosome 21 orthologs produce similar effects on skull and brain morphology of Dp(16)1Yey and Ts65Dn mice.

Trisomy 21 results in gene-dosage imbalance during embryogenesis and throughout life, ultimately causing multiple anomalies that contribute to the clinical manifestations of Down syndrome. Down syndrome is associated with manifestations of variable severity (e.g., heart anomalies, reduced growth, dental anomalies, shortened life-span). Craniofacial dysmorphology and cognitive dysfunction are consistently observed in all people with Down syndrome. Mouse models are useful for studying the effects of gene-dosage imbalance on development. We investigated quantitative changes in the skull and brain of the Dp(16)1Yey Down syndrome mouse model and compared these mice to Ts65Dn and Ts1Cje mouse models. Three-dimensional micro-computed tomography images of Dp(16)1Yey and euploid mouse crania were morphometrically evaluated. Cerebellar cross-sectional area, Purkinje cell linear density, and granule cell density were evaluated relative to euploid littermates. Skulls of Dp(16)1Yey and Ts65Dn mice displayed similar changes in craniofacial morphology relative to their respective euploid littermates. Trisomy-based differences in brain morphology were also similar in Dp(16)1Yey and Ts65Dn mice. These results validate examination of the genetic basis for craniofacial and brain phenotypes in Dp(16)1Yey mice and suggest that they, like Ts65Dn mice, are valuable tools for modeling the effects of trisomy 21 on development.

Olfaction evaluation and correlation with brain atrophy in Bardet‐Biedl syndrome

Bardet-Biedl syndrome (BBS) is a well-recognized ciliopathy characterized by cardinal features namely: early onset retinitis pigmentosa, polydactyly, obesity, hypogonadism, renal and cognitive impairment. Recently, disorders of olfaction (anosmia, hyposmia) have been also described in BBS patients. Moreover, morphological brain anomalies have been reported and prompt for further investigations to determine whether they are primary or secondary to peripheral organ involvement (i.e. visual or olfactory neuronal tissue). The objective of this article is to evaluate olfactory disorders in BBS patients and to investigate putative correlation with morphological cerebral anomalies. To this end, 20 BBS patients were recruited and evaluated for olfaction using the University of Pennsylvania Smell Identification Test (UPSIT). All of them underwent a structural magnetic resonance imaging (MRI) scan. We first investigated brain morphological differences between BBS subjects and 14 healthy volunteers. Then, we showed objective olfaction disorders in BBS patients and highlight correlation between gray matter volume reduction and olfaction dysfunction in several brain areas.

Downstream Effects of Maternal Hypothyroxinemia in Early Pregnancy: Nonverbal IQ and Brain Morphology in School-Age Children

Although maternal hypothyroxinemia is suggested to be related to various adverse consequences in a child's neurodevelopment, the underlying neurobiology is largely unknown. The objective of the study was to examine the relationship between maternal hypothyroxinemia in early pregnancy and children's nonverbal intelligence quotient (IQ). Furthermore, we explored whether global brain volumes, cortical thickness, and brain surface area differed between children exposed prenatally to hypothyroxinemia and healthy controls. The study included a large population-based prospective birth cohort in The Netherlands. A total of 3727 mother-child pairs with data on prenatal thyroid function at less than 18 weeks of gestation and nonverbal IQ at 6 years participated in the study. In 652 children, brain imaging was performed at 8 years of age. Maternal hypothyroxinemia was defined as free T4 in the lowest 5% of the sample, whereas TSH was in the normal range. At 6 years, children's IQ was assessed using a Dutch test battery. Global brain volumetric measures, cortical thickness, and surface area were assessed using high-resolution structural magnetic resonance imaging. The children of mothers with hypothyroxinemia in early pregnancy scored 4.3 points IQ lower than the children of mothers with normal thyroid status (95% confidence interval -6.68, -1.81; P = .001). After adjustment for multiple testing, we did not find any differences in brain volumetric measures, cortical thickness, and surface area between children exposed prenatally to hypothyroxinemia and controls. Our findings confirm a large adverse effect of maternal hypothyroxinemia on children's nonverbal IQ at school age. However, we found no evidence that maternal hypothyroxinemia is associated with differences in brain morphology in school-age children.

Handedness- and Hemisphere-Related Differences in Small-World Brain Networks: A Diffusion Tensor Imaging Tractography Study

Previous behavioral and scanning studies have suggested that handedness is associated with differences in brain morphology as well as in anatomical and functional lateralization. However, little is known about the topological organization of the white matter (WM) structural networks related to handedness. We employed diffusion tensor imaging tractography to investigate handedness- and hemisphere-related differences in the topological organization of the human cortical anatomical network. After constructing left hemispheric/right hemispheric weighted structural networks in 32 right-handed and 24 left-handed healthy individuals, we analyzed the networks by graph theoretic analysis. We found that both the right and left hemispheric WM structural networks in the two groups possessed small-world attributes (high local clustering and short paths between nodes), findings which are consistent with recent results from whole-brain structural networks. In addition, the right hemisphere tended to be more efficient than the left hemisphere, suggesting a high efficiency of general information processing in the right hemisphere. Finally, we found that the right-handed subjects had significant asymmetries in small-world properties (normalized clustering coefficient γ, normalized path length λ, and small-worldness σ), while left-handed subjects had fewer asymmetries. Our findings from large-scale brain networks aid in understanding the structural substrates underlying handedness-related and hemisphere-related differences in cognition and behavior.

Structural Differences in Hippocampal and Prefrontal Gray Matter Volume Support Flexible Context-Dependent Navigation Ability

Spatial navigation is a fundamental part of daily life. Humans differ in their individual abilities to flexibly navigate their world, and a critical question is how this variability relates to differences in underlying brain structure. Our experiment examined individual differences in the ability to flexibly navigate routes that overlap with, and must be distinguished from, previously learned trajectories. We related differences in flexible navigation performance to differences in brain morphology in healthy young adults using voxel-based morphometry. Our findings provide novel evidence that individual differences in gray matter volume in the hippocampus and dorsolateral prefrontal cortex correlate with our ability rapidly to learn and flexibly navigate routes through our world.

Masculinity/Femininity Predicts Brain Volumes in Normal Healthy Children

Previous research has shown sex differences in brain morphology (De Bellis et al., 2001). However, these studies have not taken gender into account. Gender is a phenotype that describes behavior. In this study, we examined the relationship between gender, sex, and brain volumes in children. One hundred and eight children ages 7 to 17 were administered the Children's Sex Role Inventory (Boldizar, 1991) and obtained volumetric brain data via magnetic resonance imaging (MRI). We found that, in the frontal lobe, higher masculinity predicted greater volumes of white matter. Also, in the temporal lobe, higher femininity predicted greater volumes of gray matter.

Cannabis-Related Working Memory Deficits and Associated Subcortical Morphological Differences in Healthy Individuals and Schizophrenia Subjects

Cannabis use is associated with working memory (WM) impairments; however, the relationship between cannabis use and WM neural circuitry is unclear. We examined whether a cannabis use disorder (CUD) was associated with differences in brain morphology between control subjects with and without a CUD and between schizophrenia subjects with and without a CUD, and whether these differences related to WM and CUD history. Subjects group-matched on demographics included 44 healthy controls, 10 subjects with a CUD history, 28 schizophrenia subjects with no history of substance use disorders, and 15 schizophrenia subjects with a CUD history. Large-deformation high-dimensional brain mapping with magnetic resonance imaging was used to obtain surface-based representations of the striatum, globus pallidus, and thalamus, compared across groups, and correlated with WM and CUD history. Surface maps were generated to visualize morphological differences. There were significant cannabis-related parametric decreases in WM across groups. Similar cannabis-related shape differences were observed in the striatum, globus pallidus, and thalamus in controls and schizophrenia subjects. Cannabis-related striatal and thalamic shape differences correlated with poorer WM and younger age of CUD onset in both groups. Schizophrenia subjects demonstrated cannabis-related neuroanatomical differences that were consistent and exaggerated compared with cannabis-related differences found in controls. The cross-sectional results suggest that both CUD groups were characterized by WM deficits and subcortical neuroanatomical differences. Future longitudinal studies could help determine whether cannabis use contributes to these observed shape differences or whether they are biomarkers of a vulnerability to the effects of cannabis that predate its misuse.

Sports and brain morphology – A voxel-based morphometry study with endurance athletes and martial artists

Physical exercises and motor skill learning have been shown to induce changes in regional brain morphology, this has been demonstrated for various activities and tasks. Also individuals with special skills show differences in regional brain morphology. This has been indicated for professional musicians, London taxi drivers, as well as for athletes like dancers, golfers and judokas. However little is known about whether sports with different metabolic profiles (aerobic vs. anaerobic) are associated with different patterns of altered brain morphology.In this cross-sectional study we investigated two groups of high-performance athletes, one group performing sports that are thought to be mainly aerobic, and one group performing sports known to have intermittent phases of anaerobic metabolism. Using high-resolution structural imaging and voxel-based morphometry (VBM), we investigated a group of 26 male athletes consisting of 13 martial artists and 13 endurance athletes as well as a group of non-exercising men (n=13).VBM analyses revealed higher gray matter (GM) volumes in the supplementary motor area/dorsal premotor cortex (BA 6) in both athlete groups as compared to the control group. In addition, endurance athletes showed significantly higher GM volume in the medial temporal lobe (MTL), specifically in the hippocampus and parahippocampal gyrus, which was not seen in the martial arts group.Our data suggest that high-performance sports are associated with changes in regional brain morphology in areas implicated in motor planning and motor learning. In addition high-level endurance sports seem to affect MTL structures, areas that have previously been shown to be modulated by aerobic exercise.