Greater Gray Matter Research Articles

Decreased frontal and orbital volumes and increased cerebellar volumes in patients with anosmia Of Unknown origin: A subtle connection?

PurposeNeuroimaging studies have shown that anosmia is accompanied by a decreased olfactory bulb volume, yet little is known about alterations in cerebral and cerebellar lobule volumes. The purpose of this study was to investigate structural brain alterations in anosmic patients. MethodsSixteen anosmic patients (mean age 42.62 ± 16.57 years; 6 women and 10 men) and 16 healthy controls (mean age 43.37 ± 18.98 years; 9 women and 7 men) were included in this retrospective study. All subjects who underwent magnetic resonance imaging scans were analyzed using VolBrain and voxel-based morphometry after olfactory testing. ResultsDespite being statistically insignificant, analysis using VBM revealed greater gray matter (GM) and white matter in the anosmia group compared to the healthy subjects. However, decreased GM (p < 0.001) and increased cerebellar (p = 0.046) volumes were observed in the anosmic patients. ConclusionsThe study revealed structural brain alterations in specific areas beyond the olfactory bulb. Our results indicate that the cerebellum may play an exceptional role in the olfactory process and that this will be worth evaluating with further dynamic neuroimaging studies.

Gray Matter Volume as Evidence for Cognitive Reserve in Bilinguals With Mild Cognitive Impairment.

Compared with monolinguals, bilinguals have a later onset of mild cognitive impairment (MCI) and Alzheimer disease symptoms and greater neuropathology at similar cognitive and clinical levels. The present study follows a previous report showing the faster conversion from MCI to Alzheimer disease for bilingual patients than comparable monolinguals, as predicted by a cognitive reserve (CR). Identify whether the increased CR found for bilinguals in the previous study was accompanied by greater gray matter (GM) atrophy than was present for the monolinguals. A novel deep-learning technique based on convolutional neural networks was used to enhance clinical scans into 1mm MPRAGEs and analyze the GM volume at the time of MCI diagnosis in the earlier study. Twenty-four bilingual and 24 monolingual patients were diagnosed with MCI at a hospital memory clinic. Bilingual patients had more GM loss than monolingual patients in areas related to language processing, attention, decision-making, motor function, and episodic memory retrieval. Bilingualism and age were the strongest predictors of atrophy after other variables such as immigration and education were included in a multivariate model. CR from bilingualism is evident in the initial stages of neurodegeneration after MCI has been diagnosed.

Sex differences in frontotemporal atrophy in CADASIL revealed by 7-Tesla MRI

Brain damage caused by small vessel disease (SVD) differs between males and females. We aimed to examine the pure sex-specific neuroanatomical mechanisms of SVD adjusted for voxel-based expected effects of age and sex on healthy brain volume. Thirty-one female and 32 male genetic SVD (cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy, CADASIL) patients and 55 sex- and age-matched healthy controls (HCs) underwent 7-Tesla MRI examinations. Voxel-based W-score maps were calculated from volumes and deformations of brain tissues, controlling for the expected effects of age and sex in HCs. Significant cognitive declines in working memory and executive function were identified in male CADASIL patients compared to female patients. Greater gray matter (GM) atrophy was found in the bilateral orbitofrontal cortex (OFC), left anterior cingulate cortex (ACC), left entorhinal cortex (EC), and right temporooccipital cortex in male CADASIL patients than in females. Working memory was associated with volumes in the right OFC specific to female CADASIL patients, whereas visuospatial ability was associated with the right hOcl (primary visual area, BA 17) volume specific to males. The current findings indicate that sex affects the pathogenesis of CADASIL, ranging from differences in neuroanatomy to those in behavioral performance, which may facilitate the development of more effective sex-specific therapeutic strategies for CADASIL and SVD.

NEUROLOGICAL CORRELATES OF SOCIAL BONDING AND BRIDGING

Abstract Social connectedness has been linked to decreased rates of cognitive decline in later life. However, recent work suggests that particular social network characteristics (i.e., bonding and bridging) may buffer against age-related degeneration. The present study analyzes social network and structural MRI data of 176 older adults from the Social Networks and Alzheimer’s Disease (SNAD) study. Results indicate that increased social bridging is associated with greater grey matter (GM) volume in several limbic structures. Increased social bonding is associated with greater GM volumes in several cerebral cortex structures as well as greater volumes in some components of the limbic system. Most notably, the effects of bridging are primarily lateralized in the left hemisphere while the effects of bonding are observed mostly in the right hemisphere. These results suggest that the neurocognitive benefits of social connectedness depend on the preponderance of bridging and/or bonding ties in older adults’ social networks.

Changes of Brain Structures and Psychological Characteristics in Predatory, Affective Violent and Nonviolent Offenders.

Purpose: Violent subjects were demonstrated to exhibit abnormal brain structures; however, the brain changes may be different between criminals committing affective (VA), predatory violence (VP), and non-violence (NV). Therefore, the purpose of this study was to compare the differences in brain structures and psychological characteristics between VA, VP, and NV offenders. Methods: Twenty male criminal subjects (7 VP; 6 VA; and 7 NV) offenders; and twenty age-matched male healthy non-criminals were enrolled in this study. All subjects received psychological assessments as well as magnetic resonance imaging scans of the brain. Analysis of variance (ANOVA) was performed to understand the differences among four groups with Bonferroni correction. The voxel-based morphometry and voxel-wise diffusion tensor imaging analyses were performed to compare the gray matter (GM) volume and white matter (WM) integrity between the groups. In significant regions, a Spearman correlation analysis was performed to understand the relationship between the brain changes and psychological scores. Results: The ANOVA analysis showed that AUDIT scores were significantly different among four groups, but no significant group difference was noted after Bonferroni correction. The imaging comparisons further demonstrated that the VP and NV offenders exhibited significant alterations of WM and GM tissues in the rectus and superior temporal gyrus, respectively. In addition, the VP offenders exhibited greater GM volumes than VA offenders in the right middle frontal gyrus, and NV offenders had greater GM volumes than VP offenders in the bilateral thalamus. Conclusion: We concluded that the VA, VP, and NV groups exhibited different degrees of alterations in GM and WM tissues in regions involved in emotion and cognition.

Increased Gray Matter Volume Induced by Chinese Language Acquisition in Adult Alphabetic Language Speakers.

It is interesting to explore the effects of second language (L2) acquisition on anatomical change in brain at different stages for the neural structural adaptations are dynamic. Short-term Chinese training effects on brain anatomical structures in alphabetic language speakers have been already studied. However, little is known about the adaptations of the gray matter induced by acquiring Chinese language for a relatively long learning period in adult alphabetic language speakers. To explore this issue, we recruited 38 Indian overseas students in China as our subjects. The learned group included 17 participants who had learned Mandarin Chinese for an average of 3.24 years and achieved intermediate Chinese language proficiency. The control group included 21 subjects who had no knowledge about Chinese. None of the participants had any experience in learning logographic and tonal language before Chinese learning. We found that (1) the learned group had significantly greater gray matter volume (GMV) in the left lingual gyrus (LG) compared with the control group; (2) the Chinese characters’ reading accuracy was significantly and positively correlated to the GMV in the left LG and fusiform gyrus (FG) across the two groups; and (3) in the learned group, the duration of Chinese learning was significantly and positively correlated with the GMV in the left inferior frontal gyrus (IFG) after correction for multiple comparisons with small volume corrections. Our structural imaging findings are in line with the functional imaging studies reporting increased brain activation induced by Chinese acquisition in alphabetic language speakers. The regional gray matter changes reflected the additional requirements imposed by the more difficult processing of Chinese characters and tones. The present study also show that the biological bases of the adaptations induced by a relatively long period of Chinese learning were limited in the common areas for first and foreign language processing.

Increased Cerebellar Gray Matter Volume in Athletes: A Voxel-Wise Coordinate-Based Meta-Analysis

ABSTRACT Purpose: The purpose of this systematic review and meta-analysis study was to investigate distinct brain structural characteristics in athletes as compared with those in non-athletes by quantifying regional gray matter (GM) volume changes using voxel-based morphometry analysis based on a whole-brain approach.Methods: The systematic literature search was conducted from November 1, 2020 to October 18, 2021 via the two search engines including the PubMed and Web of Science. We included 13 studies that reported GM volume data in 229 athletes as compared 219 non-athletes based on the whole-brain analysis with specific three-dimensional coordinates in a standard stereotactic space. Thus, we performed a coordinate-based meta-analysis using the seed-based d mapping via permutation of subject images methods.Result: The coordinate-based meta-analysis reported that the athletes significantly reveal greater regional GM volume across right cerebellar lobules IV–V and Brodmann area 37 regions than those in the non-athletes with minimal levels of heterogeneity and publication bias between the included studies. The subgroup analyses show that greater GM volume for athletes in closed-skill sports appeared across the right cerebellar hemispheric lobules VIII and the right cingulum than those for non-athletes.Conclusion: These cumulative findings from multiple brain imaging studies suggest potential brain plasticity evidence in the athletes who experienced extensive motor training.

Musical experience relates to functional connectivity in older adults

Previous studies have shown that engaging in musical activities throughout the lifespan may buffer age-related decline in auditory and motor function, as well as in general cognitive function. MRI studies have demonstrated that individuals with musical training and experience exhibited greater grey matter volume and functional connectivity in extensive brain regions, especially in auditory and motor systems, compared to matched controls with no particular musical training or experience. Therefore, musical activity is a potential protective factor for brain health across lifespan. However, how lifespan musical experience shapes functional connectivity in older adults is still unknown. The current analysis investigated whether general musical experience (Goldsmith Music Sophistication Index) is associated with functional connectivity in older adults (age=65.7±4.4, n=69), focusing on seed regions in primary motor areas (bilateral precentral gyrus) and primary auditory regions (bilateral anterior/posterior superior temporal gyrus) and their functional connectivity towards other areas throughout the whole brain. We found that older adults with more musical experience showed greater functional connectivity between anterior superior temporal gyrus and insula (R2=0.10, p=0.01), and between posterior superior temporal gyrus and cerebellum (R2=0.08, p=0.02). However, musical experience and music-related functional connectivity was not significantly correlated with general cognitive functions in our sample. Overall, our findings suggest that older adults with more musical experience might be more efficient in some aspects of auditory processing and auditory-motor skills, but this may not transfer towards domain-general cognitive tests. Our results support the notion that even non-professional engagement in musical experiences may afford benefits to the aging brain.

The Role of Race in Relations of Social Support to Hippocampal Volumes Among Older Adults.

Evidence suggests social support may buffer brain pathology. However, neither its association with hippocampal volume, a marker of Alzheimer's disease risk, nor the role of race in this association has been fully investigated. Multiple regression analyses examined relations of total social support to magnetic resonance imaging-assessed gray matter (GM) hippocampal volumes in the total sample (n = 165; mean age = 68.48 year), and in race-stratified models of African American and White older adults, adjusting for select covariates. Results showed greater social support was associated with greater GM hippocampal volumes among African American older adults only (p < .01). Our findings suggest greater total social support may play a role in supporting the hippocampus, particularly among African American older adults, who had lower hippocampal volumes than their White counterparts. Further research is needed to test these questions longitudinally and examine which aspects of social support may promote hippocampal integrity, specifically.

Effects of Spaceflight Stressors on Brain Volume, Microstructure, and Intracranial Fluid Distribution.

Astronauts are exposed to elevated CO2 levels onboard the International Space Station. Here, we investigated structural brain changes in 11 participants following 30-days of head-down tilt bed rest (HDBR) combined with 0.5% ambient CO2 (HDBR + CO2) as a spaceflight analog. We contrasted brain changes observed in the HDBR + CO2 group with those of a previous HDBR sample not exposed to elevated CO2. Both groups exhibited a global upward shift of the brain and concomitant intracranial free water (FW) redistribution. Greater gray matter changes were seen in the HDBR + CO2 group in some regions. The HDBR + CO2 group showed significantly greater FW decrements in the posterior cerebellum and the cerebrum than the HDBR group. In comparison to the HDBR group, the HDBR + CO2 group exhibited greater diffusivity increases. In half of the participants, the HDBR + CO2 intervention resulted in signs of Spaceflight Associated Neuro-ocular Syndrome (SANS), a constellation of ocular structural and functional changes seen in astronauts. We therefore conducted an exploratory comparison compared between subjects that did and did not develop SANS and found asymmetric lateral ventricle enlargement in the SANS group. These results enhance our understanding of the underlying mechanisms of spaceflight-induced brain changes, which is critical for promoting astronaut health and performance.

Greater Social Engagement and Greater Gray Matter Microstructural Integrity of Aging Adults

Social engagement reflects habitual social roles in aging adults and may protect against dementia. Cross-sectional associations of social engagement (SE) index with gray matter (GM) microstructure was studied in regions of interest relevant to social cognition among community-dwelling older adults [n=293, mean age: 82.8 years (SD: 2.8), 43% males] using linear regression models. Greater SE was significantly related to lower mean diffusivity (MD) (greater GM microstructural integrity) [shown as standardized estimate (p-value)] in: left middle frontal gyrus-orbital part: -0.168 (0.005), left caudate nucleus: -0.141 (0.02), left temporal pole-middle temporal gyrus: -0.136 (0.03), right middle frontal gyrus: -0.160 (0.006), right superior frontal gyrus-orbital part: -0.187 (0.002), right middle frontal gyrus, orbital part: -0.124 (0.04), adjusted for demographic attributes. Associations were robust to adjustment for hearing or ADL difficulty. Findings were generally stronger in females than in males. Social engagement may prevent GM integrity loss and build brain reserve in dementia-related regions. Part of a symposium sponsored by Brain Interest Group.

Most of Clinically Unresponsive Patients Present Richer Brain Activity than Expected: Lessons from a Multimodal Neuroimaging Study

Background: A significant proportion of brain-injured patients who are unresponsive at the bedside (i.e., unresponsive wakefulness syndrome – UWS) may present brain activity similar to patients in minimally conscious state (MCS). This peculiar condition has been termed “non-behavioural MCS” or “MCS*”. Methods: Brain 18 F-fluorodeoxyglucose Positron Emission Tomography (FDG-PET) was acquired on 135 brain-injured patients diagnosed in prolonged UWS (n=48) or MCS (n=87). Clinical diagnosis was based on repeated Coma Recovery Scale-Revised assessments. Relative metabolic preservation in the fronto-parietal network (measured with standardized uptake value) was evaluated by 3 experts blinded to the clinical diagnosis. Patients with hypometabolism of the fronto-parietal network were labelled UWS, while preservation either confirmed the behavioural diagnosis of MCS or, in absence of behavioural signs of consciousness, suggested a diagnosis of MCS*. The clinical outcome at 1-year follow-up, the functional connectivity (measured with electroencephalography), the grey matter atrophy (assessed with magnetic resonance imaging), and the regional brain metabolic patterns were investigated in the three groups (UWS, MCS* and MCS). Findings: Out of the 48 behavioural UWS patients, 32 (67%) presented a partial preservation of brain metabolism (i.e., MCS*). Compared to the hypometabolic UWS patients, MCS* patients demonstrated a better outcome, higher global functional connectivity in the alpha and theta bands, as well as greater grey matter preservation in the frontal and temporal regions, the fusiform gyrus, and the insula. MCS* patients presented lower brain metabolism mostly in the posterior regions compared to MCS patients. Interpretation: MCS* is a frequent phenomenon that is also associated with a better outcome than the diagnosis of UWS. Complementary exams should be provided to all unresponsive patients before taking medical decisions. Funding Statement: Belgian National Funds for Scientific Research, Human Brain Project SGA3 (No. 945539), DOCMA project (EU-H2020-MSCA–RISE–778234), Belgian Federal Science Policy Office (PRODEX), Bial Foundation, fund Generet, King Baudouin Foundation, AstraZeneca Foundation. Declaration of Interests: The authors declare that there is no conflict of interest regarding the publication of this paper. Ethics Approval Statement: The study was approved by the Ethics Committee of the Faculty of Medicine of the University of Liege. Written informed consent was obtained from healthy controls and patients' legal representatives.

Brain voxel-based morphometry correlates of emotion dysregulation in attention-deficit hyperactivity disorder

Attention-deficit hyperactivity disorder (ADHD) has a high prevalence of co-occurring with emotion dysregulation (ED). Youths with ADHD and ED are more likely to have increased functional impairment. There is accumulating research on defining the features, behavioral, and physiological manifestations of ED, but there are currently few studies elucidating neuroanatomical correlations of ED in ADHD. Structural magnetic resonance imaging data from 118 children (aged 7-18years) with ADHD (50 ADHD+high ED, 68 ADHD+low ED), and 104 typically developing controls (TDC) were processed using voxel-based morphometry. We used both dichotomous and continuous indices of ED to examine the possible correspondence between ED and ADHD. Relative to ADHD+high ED, ADHD+low ED had greater gray matter (GM) volumes over the left anterior prefrontal cortex (PFC). ADHD+low ED and ADHD+high ED shared a negative association of ED levels with the left middle temporal pole GM volume. TDC and ADHD+low ED also shared negative relationships of ED levels with the right temporal volume, and positive relationships with the left dorsolateral PFC volume. Besides, ED-by-group interactions were also noted. Specifically, medial PFC GM volumes increased and decreased with ED severity in ADHD+low ED and ADHD+high ED, respectively; and left cerebellum Crus GM volumes decreased and increased with ED severity in ADHD+low ED and ADHD+high ED, respectively. Our findings add to the evidence that some specific neural correlates are underpinning ED across ADHD and TDC. These findings suggest the importance of incorporating ED problems when considering heterogeneity in studies of ADHD.

0305 Grey Matter Volumetric Differences are Predictive of Attentional Lapses During Sleep Deprivation

Abstract Introduction Inter-individual differences in resistance to cognitive effects of sleep loss are well established and extend from basic vigilance capacities to more nuanced emotional processing. Neurobiological markers related to gray matter volumetric differences associated with resilience to sleep deprivation (SD) have yet to be explored. We collected anatomical magnetic resonance imaging on well-rested healthy adults and correlated gray matter volume (GMV) with the number of lapses on a psychomotor vigilance test (PVT) subsequently occurring over 29-hours of SD. Methods 45 individuals (23 males; mean age: 25.36 ± 5.62y) completed a baseline neuroimaging session while well-rested and returned 2-4 days later to complete 29h of SD. The PVT was administered at one-hour intervals across SD. High-resolution T1 structural scans were used for a volume-based morphometric analysis (CAT12). Images were segmented and normalized following automated procedures and smoothed at 8 mm FWHM. Regions of interest were constrained to the anterior cingulate and ventral frontal areas of the cortex. GM volume was correlated with the total number of lapses across all PVT administrations, after controlling for age, sex, and total intracranial volume. Results Total number of lapses positively correlated with GMV in two clusters comprised of areas in the anterior cingulate cortex (FWE corrected, p = 0.046), as well as the opercular and triangular parts of the inferior frontal gyrus (FWE corrected, p = 0.006). Conclusion Susceptibility to attentional lapses was predicted by greater gray matter volume in the ventrolateral prefrontal and anterior cingulate cortices. Current findings support that individual differences in attentional resiliency during SD may be, in part, due to differences in gray matter volume within cortical areas previously shown to be functionally affected by sleep loss. Support DARPA (12-12-11-YFA11-FP-029)

0314 Resilience to Inhibitory Deficits During Sleep Deprivation is Predicted by Gray Matter Volume in the Ventrolateral and Ventromedial Prefrontal Cortex

Abstract Introduction Stable, trait-like inter-individual resilience to sleep loss has been demonstrated for psychomotor vigilance, mood, subjective sleepiness, and some reasoning tasks, some of which have been associated with specific genetic or neurobiological markers. Resilience to executive control deficits induced by sleep deprivation (SD) has not been explored in terms of neurobiological markers. We, therefore, collected magnetic resonance imaging (MRI) scans of healthy individuals when well rested and correlated gray matter volume with resistance to inhibitory declines during 29 hours of SD. Methods Forty-five healthy individuals (22 female) ranging in age from 20 to 43 underwent structural MRI. Within 2-4 days after scanning, participants returned to the lab to undergo one night of SD, during which they completed a standard go/no-go task involving inhibitory processing every 4 hours. Scores were calculated as throughput (correct responses per working minute). The difference between performance in the evening (22:45) versus the performance the next morning (06:45) was calculated as an index of “inhibitory resilience.” Gray matter volume was regressed against the inhibitory resilience measure. Based on prior research, regions were constrained to the ventrolateral prefrontal cortex and ventromedial prefrontal cortex. Results Greater resilience against declines in inhibitory capacity during SD was predicted by 1) larger gray matter volume within the ventrolateral prefrontal cortex and 2) reduced volume within the ventromedial prefrontal cortex (p&amp;lt;.05, FWE cluster corrected). These two clusters contributed significant unique explanatory variance to the model (R2=.45, p&amp;lt;.0001). Conclusion The ability to sustain performance during an inhibitory go/no-go task during SD was predicted by greater gray matter volume within the ventrolateral prefrontal cortex, a region that has been previously associated with inhibitory capacity, and reduced volume within an area of the ventromedial prefrontal cortex, which is often related to the default mode network. Findings suggest that specific brain networks may confer task-specific resistance to SD. Support Defense Advanced Research Projects Agency, DARPA Young Faculty Award: DARPA-12-12-11-YFA-FP-029

0082 Hippocampal Gray Matter Volume in Healthy Adult Population is Associated with Habitual Sleep Duration

Abstract Introduction The hippocampus is well known for its role in sleep and memory consolidation in adolescents, and has been shown to demonstrate neural plasticity and neuronal regeneration. However, the relationship between sleep and hippocampal gray matter volume in healthy adults remains to be fully characterized. We hypothesized that total sleep time (TST), as measured by actigraphy, would correlate positively with gray matter volume (GMV) in the hippocampus, a key memory region of the brain. Methods Forty-five healthy normal sleeping adults between 20–45 years of age wore an actigraph for seven days to quantify habitual sleep duration and underwent magnetic resonance imaging during the actigraphy period. Voxel based morphometry in SPM12 was used to estimate GMV at the whole brain level. A region-of-interest mask was used to constrain data analysis to the left and right hippocampi. Results Habitual sleep duration per night correlated positively with gray matter volume within part of the left hippocampus (x=-36,y=-20,z=-18; k=32, pFWE-corr=0.093), controlling for age, sex, total intracranial volume, intelligence scores and mood. No correlation was found between TST and hippocampal GMV in the right hippocampus. Conclusion Longer sleep time was associated with greater gray matter volume in the left hippocampus. This finding is consistent with what has been observed in healthy children and extend these findings to healthy normal sleeping adults. While TST and GMV are correlated, the causal association cannot be established here. Further research may explore the effects of sleep extension on GMV and how these volume differences associate with various aspects of cognition, particularly memory. It should be noted that this study only included healthy adults with sleep durations between 6–9 hours per night. Future studies would benefit from including adults with a greater variance in their sleep patterns to better understand the relationship between sleep and hippocampal volume, and its potential effects on memory performance. Support Defense Advanced Research Projects Agency Young Faculty Award: DARPA-12-12-11-YFA11-FP-029

0315 Gray Matter Volume of the Rostral Medial Prefrontal Cortex is Associated with Resilience to Mood Decline During Overnight Sleep Deprivation

Abstract Introduction Vulnerability to sleep deprivation (SD) has been attributed to inter-individual trait-like differences in the ability to sustain vigilance and subjective alertness, which may have distinct neurobiological substrates. We have previously shown that reduced suppression of the Default Mode Network (DMN) during a cognitive task was predictive of global vulnerability to SD. However, little is known about vulnerability to mood decrements during SD and the underlying neurobiological mechanisms. Using voxel-based morphometry (VBM), we assessed structural differences in gray matter volume (GMV) of a region of the anterior DMN, the medial prefrontal cortex and its association with self-reported mood during 29 hours of SD. Methods 45 healthy participants (23 male; Ages 20-43) underwent 3T structural magnetic resonance imaging (MRI). Within 4 days, participants underwent an overnight SD session (29 hours awake total) which included hourly mood assessments with several visual analog mood scales (VAMS) assessing positive and negative affect. Hourly VAMS data were converted into a comparative metric of percent worsening of mood scores from 19:00 until noon the next day. These scores were averaged to determine a “mood resilience” score, with higher scores indicating greater mood sustainment. Using SPM12, the mean mood resilience scores were correlated with whole-brain gray matter volume, restricted to the medial prefrontal cortex, p&amp;lt;.05, FWE corrected, with a cluster threshold of 137 voxels. Results Overnight mood resilience was significantly correlated with greater grey matter volume in right rostral medial prefrontal cortex (p&amp;lt;.05, corrected; k=137). Conclusion Individuals with greater gray matter volume within a circumscribed region of the right medial prefrontal cortex demonstrated greater resilience to mood degradation over 29 hours of continuous wakefulness. This same region of the brain has been shown to be critical for the passive maintenance of emotions. We speculate that greater GMV could protect against mood decline by better sustaining emotional state during SD. Support Defense Advanced Research Projects Agency Young Faculty Award: DARPA-12-12-11-YFA11-FP-029

Social support modulates the association between PTSD diagnosis and medial frontal volume in Chinese adults who lost their only child

Losing an only child is a devastating life event that a parent can experience and may lead to post-traumatic stress disorder (PTSD). Social support could buffer against the negative influence of this trauma, but the neural mechanism underlying this alleviation effect remains poorly understood. In this study, voxel-based morphometry was conducted on brain MRI of 220 Han Chinese adults who had lost their only child. We performed multiple regression analysis to investigate the associations between social support scores – along with PTSD diagnosis, age, sex, body mass index (BMI) – and brain grey matter (GM) volumes in these bereaved parents. For all trauma-exposed adults, social support-by-diagnosis interaction was significantly associated with medial prefrontal volume (multiple comparisons corrected P ˂ 0.05), where positive correlation was found in adults with PTSD but not in those without PTSD. Besides, PTSD diagnosis was associated with decreased GM volume in medial and middle frontal gyri (P ˂ 0.001, uncorrected); older age was associated with widespread GM volume deficits; male sex was associated with lower GM volume in rolandic operculum, insular, postcentral gyrus (corrected P ˂ 0.05), and lower GM in thalamus but greater GM in parahippocampus (P ˂ 0.001, uncorrected); higher BMI was associated with GM deficits in occipital gyrus (corrected P ˂ 0.05) and precuneus (P ˂ 0.001, uncorrected). In conclusions, social support modulates the association between PTSD diagnosis and medial frontal volume, which may play an important role in the emotional disturbance in PTSD development in adults who lost their only child.

Culture-Related and Individual Differences in Regional Brain Volumes: A Cross-Cultural Voxel-Based Morphometry Study.

Converging behavioral and functional neuroimaging evidence indicates that East Asian and Western individuals have different orientations for processing information that may stem from contrasting cultural values. In this cross-cultural magnetic resonance imaging (MRI) study, we used voxel-based morphometry (VBM) approach to investigate culture-related and individual differences of independent-interdependent orientation in structural brain volume between 57 Taiwanese and 56 Western participants. Each participant’s degree of endorsement of independent and interdependent cultural value was assessed by their self-report on the Singelis Self-Construal Scale (SCS). Behaviorally, Taiwanese rated higher SCS scores than Westerners in interdependent value and Westerners rated higher SCS scores than Taiwanese in independent value. The VBM results demonstrated that Western participants showed greater gray matter (GM) volume in the fronto-parietal network, whereas Taiwanese participants showed greater regional volume in temporal and occipital regions. Our findings provide supportive evidence that socio-cultural experiences of learned independent-interdependent orientations may play a role in regional brain volumes. However, strategic differences in cognition, genetic variation, and/or modulations of other environmental factors should also be considered to interpret such culture-related effects and potential individual differences.

1334-P: Structural Brain Differences between Adolescents with Type 2 Diabetes and Obese Controls

Recent studies have shown differences in brain structure between adolescents with type 2 diabetes (T2D) and their nondiabetic peers. Compared to obese controls (OCs), global white matter (WM) and regional gray matter (GM) differences have been found. Our aim was to evaluate further for global and regional differences in GM, WM, and parenchymal (GM and WM combined) brain volume between youth with T2D and nondiabetic OCs. We compared 11 youth with T2D (mean age 17.1 ±2.0 years, mean HbA1c 8.6 ±2.5%) and 11 age, race and sex similar OCs (mean HbA1c 5.3 ±0.2%). Participants underwent high-resolution T1-weighted MRI scans, analyzed using voxel-based morphometry. Tissue volumes were normalized across participants by dividing by each individual’s intracranial volume (ICV). The normalized global volumes were compared between the two groups, and statistical significance was determined at p&amp;lt;0.05. For regional analyses, statistical significance for each voxel was established at p &amp;lt;0.05 using a family-wise error rate procedure, reporting only clusters with ≥200 contiguous voxels. Compared to OCs, adolescents with T2D had significantly lower parenchymal brain volume (parenchymal/ICV ratio 0.843 in T2D vs. 0.856 in OC, p=0.04). There were no significant differences in global GM (GM/ICV ratio 0.514 in T2D vs. 0.517 in OC, p=0.76) or global WM (WM/ICV ratio 0.329 in T2D vs. 0.340 in OC, p=0.10), although global WM did trend toward significance. In addition, there were 3 brain regions in the T2D group that had lower GM volume than OCs, and 2 regions in which the T2D group had greater GM volume. Adolescents with T2D show significantly lower parenchymal brain volume compared to age, race, and sex similar OCs. This difference may be attributable to lower WM volume, but a larger sample size is needed. No global GM differences were found between groups, but regional differences in GM were identified. These data support the hypothesis that, independent of obesity, structural brain differences may exist in adolescents with T2D. Disclosure J.M. Redel: None. M.W. DiFrancesco: None. G.R. Lee: None. L.M. Dolan: None. A.S. Shah: None. Funding Endocrine Fellows Foundation; Cincinnati Diabetes and Obesity Center; Cincinnati Children's