Matter Density In Brain Regions Research Articles

Amygdala 5-HTT Gene Network Moderates the Effects of Postnatal Adversity on Attention Problems: Anatomo-Functional Correlation and Epigenetic Changes.

Variations in serotoninergic signaling have been related to behavioral outcomes. Alterations in the genome, such as DNA methylation and histone modifications, are affected by serotonin neurotransmission. The amygdala is an important brain region involved in emotional responses and impulsivity, which receives serotoninergic input. In addition, studies suggest that the serotonin transporter gene network may interact with the environment and influence the risk for psychiatric disorders. We propose to investigate whether/how interactions between the exposure to early life adversity and serotonin transporter gene network in the amygdala associate with behavioral disorders. We constructed a co-expression-based polygenic risk score (ePRS) reflecting variations in the function of the serotonin transporter gene network in the amygdala and investigated its interaction with postnatal adversity on attention problems in two independent cohorts from Canada and Singapore. We also described how interactions between ePRS-5-HTT and postnatal adversity exposure predict brain gray matter density and variation in DNA methylation across the genome. We observed that the expression-based polygenic risk score, reflecting the function of the amygdala 5-HTT gene network, interacts with postnatal adversity, to predict attention and hyperactivity problems across both cohorts. Also, both postnatal adversity score and amygdala ePRS-5-HTT score, as well as their interaction, were observed to be associated with variation in DNA methylation across the genome. Variations in gray matter density in brain regions linked to attentional processes were also correlated to our ePRS score. These results confirm that the amygdala 5-HTT gene network is strongly associated with ADHD-related behaviors, brain cortical density, and epigenetic changes in the context of adversity in young children.

Comparison of brain structure between pain-susceptible and asymptomatic individuals following experimental induction of low back pain

Background ContextPeripheral differences often do not adequately account for variation in reports of pain intensity in people with musculoskeletal pain. PurposeHere we sought to determine the extent to which structural differences in the brain (grey matter density) of pain free individuals might relate to subsequent pain (or lack thereof) after standardized peripheral muscle injury (ie, micro trauma from high intensity exercise). Study DesignThis was an observational laboratory-based study that was a secondary analysis from a larger trial. MethodsParticipants completed baseline testing (functional MRI and quantitative pain testing) followed by high intensity trunk exercise to induce delayed onset muscle soreness in the erector spinae. Forty-eight hours later, back pain intensity ratings were collected and all participants were re-imaged. Grey matter density was determined using voxel-based morphometry. The “asymptomatic” group (no reports of any pain within 48 hours after induction) to a ‘pain’ group (rating of pain at rest and movement pf>20 on a 101-point numeric rating scale). ResultsOur results revealed several large clusters where, compared to participants with pain, asymptomatic participants had significant greater grey matter density. These brain regions included left medial frontal gyrus, left middle occipital gyrus, left middle temporal gyrus, left inferior frontal gyrus, and right superior frontal gyrus. ConclusionsLower grey matter density in brain regions previously linked to discriminative, emotional, and cognitive aspects of cortical processing are associated with reporting musculoskeletal pain after a standardized peripheral muscle injury. Clinical SignificanceCortical gray matter density of people without any pain may influence response to a standardized high intensity exercise protocol. This finding adds further support to the relevance of central factors in explaining the tremendous individual variability in pain report following acute musculoskeletal injury.

Juggling revisited — A voxel–based morphometry study with expert jugglers

Juggling is a highly interesting tool to investigate neuroplasticity associated with motor-learning. Several brain-imaging studies have reported changes in regional brain morphology in visual association cortices in individuals learning how to juggle a three-ball cascade. However, to our knowledge there are no studies that investigated expert jugglers, looking for specific features in regional brain morphology related to this highly specialized skill.Using T1-weighted images and voxel-based morphometry we investigated in a cross-sectional study design 16 expert jugglers, able to juggle at least five balls and an age- and gender-matched group of non-jugglers. We hypothesized that expert jugglers would show higher gray matter density in regions involved in visual motion perception and eye-hand coordination. Images were pre-processed and analyzed using SPM8. Age was included in the analyses as covariate of no interest.As compared to controls jugglers displayed several clusters of higher, regional gray matter density in the occipital and parietal lobes including the secondary visual cortex, the hMT+/V5 area bilaterally and the intraparietal sulcus bilaterally. Within the jugglers group we also found a correlation between performance and regional gray matter density in the right hMT+/V5 area.Our study provides evidence that expert jugglers show increased gray matter density in brain regions involved in visual motion perception and eye–hand coordination, i.e. brain areas that have previously been shown to undergo dynamic changes in terms of gray matter increases in subjects learning a basic three-ball cascade. The extent to which transient increases in beginners and the differences in experts and non-experts are based on the same neurobiological correlates remains to be fully elucidated.

Smoking Is Associated With Reduced Cortical Regional Gray Matter Density in Brain Regions Associated With Incipient Alzheimer Disease

The results of observational studies suggest that smoking increases the risk of Alzheimer disease (AD). The authors designed this study to determine if older people who smoke have decreased gray matter density in brain regions associated with incipient AD. The authors recruited 39 pairs (N = 78) of smokers/never-smokers 70 to 83 years of age who were matched for age, sex, education, and handedness. Participants were free of clinically significant cognitive impairment, depression, stroke, or other serious medical conditions. Gray matter density was determined by voxel-based morphometry using statistical parametric mapping of T1-weighted magnetic resonance images. Smokers had decreased gray matter density in the posterior cingulum and precuneus (bilateral), right thalamus, and frontal cortex (bilateral) compared with never-smokers. Smoking is associated with decreased gray matter density in brain regions previously associated with incipient AD. Longitudinal investigations are required to clarify whether these changes are progressive in nature.

6.20 Active control of knee flexion during the step off an unexpected compliant surface to maintain similar toe clearance

Juggling is a highly interesting tool to investigate neuroplasticity associated with motor-learning. Several brain-imaging studies have reported changes in regional brain morphology in visual association cortices in individuals learning how to juggle a three-ball cascade. However, to our knowledge there are no studies that investigated expert jugglers, looking for specific features in regional brain morphology related to this highly specialized skill.Using T1-weighted images and voxel-based morphometry we investigated in a cross-sectional study design 16 expert jugglers, able to juggle at least five balls and an age- and gender-matched group of non-jugglers. We hypothesized that expert jugglers would show higher gray matter density in regions involved in visual motion perception and eye-hand coordination. Images were pre-processed and analyzed using SPM8. Age was included in the analyses as covariate of no interest.As compared to controls jugglers displayed several clusters of higher, regional gray matter density in the occipital and parietal lobes including the secondary visual cortex, the hMT +/V5 area bilaterally and the intraparietal sulcus bilaterally. Within the jugglers group we also found a correlation between performance and regional gray matter density in the right hMT +/V5 area.Our study provides evidence that expert jugglers show increased gray matter density in brain regions involved in visual motion perception and eye–hand coordination, i.e. brain areas that have previously been shown to undergo dynamic changes in terms of gray matter increases in subjects learning a basic three-ball cascade. The extent to which transient increases in beginners and the differences in experts and non-experts are based on the same neurobiological correlates remains to be fully elucidated.