1. |
- Draganski, Bogdan, et al.
(författare)
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Temporal and spatial dynamics of brain structure changes during extensive learning.
- 2006
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Ingår i: The Journal of neuroscience : the official journal of the Society for Neuroscience. - 1529-2401. ; 26:23, s. 6314-7
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Tidskriftsartikel (refereegranskat)abstract
- The current view regarding human long-term memory as an active process of encoding and retrieval includes a highly specific learning-induced functional plasticity in a network of multiple memory systems. Voxel-based morphometry was used to detect possible structural brain changes associated with learning. Magnetic resonance images were obtained at three different time points while medical students learned for their medical examination. During the learning period, the gray matter increased significantly in the posterior and lateral parietal cortex bilaterally. These structural changes did not change significantly toward the third scan during the semester break 3 months after the exam. The posterior hippocampus showed a different pattern over time: the initial increase in gray matter during the learning period was even more pronounced toward the third time point. These results indicate that the acquisition of a great amount of highly abstract information may be related to a particular pattern of structural gray matter changes in particular brain areas.
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2. |
- Giannakopoulos, Panteleimon, et al.
(författare)
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Alzheimer resemblance atrophy index, BrainAGE, and normal pressure hydrocephalus score in the prediction of subtle cognitive decline : added value compared to existing MR imaging markers.
- 2022
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Ingår i: European Radiology. - : Springer Science and Business Media LLC. - 0938-7994 .- 1432-1084. ; 32:11, s. 7833-7842
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES: Established visual brain MRI markers for dementia include hippocampal atrophy (mesio-temporal atrophy MTA), white matter lesions (Fazekas score), and number of cerebral microbleeds (CMBs). We assessed whether novel quantitative, artificial intelligence (AI)-based volumetric scores provide additional value in predicting subsequent cognitive decline in elderly controls.METHODS: A prospective study including 80 individuals (46 females, mean age 73.4 ± 3.5 years). 3T MR imaging was performed at baseline. Extensive neuropsychological assessment was performed at baseline and at 4.5-year follow-up. AI-based volumetric scores were derived from 3DT1: Alzheimer Disease Resemblance Atrophy Index (AD-RAI), Brain Age Gap Estimate (BrainAGE), and normal pressure hydrocephalus (NPH) index. Analyses included regression models between cognitive scores and imaging markers.RESULTS: AD-RAI score at baseline was associated with Corsi (visuospatial memory) decline (10.6% of cognitive variability in multiple regression models). After inclusion of MTA, CMB, and Fazekas scores simultaneously, the AD-RAI score remained as the sole valid predictor of the cognitive outcome explaining 16.7% of its variability. Its percentage reached 21.4% when amyloid positivity was considered an additional explanatory factor. BrainAGE score was associated with Trail Making B (executive functions) decrease (8.5% of cognitive variability). Among the conventional MRI markers, only the Fazekas score at baseline was positively related to the cognitive outcome (8.7% of cognitive variability). The addition of the BrainAGE score as an independent variable significantly increased the percentage of cognitive variability explained by the regression model (from 8.7 to 14%). The addition of amyloid positivity led to a further increase in this percentage reaching 21.8%.CONCLUSIONS: The AI-based AD-RAI index and BrainAGE scores have limited but significant added value in predicting the subsequent cognitive decline in elderly controls when compared to the established visual MRI markers of brain aging, notably MTA, Fazekas score, and number of CMBs.KEY POINTS: • AD-RAI score at baseline was associated with Corsi score (visuospatial memory) decline. • BrainAGE score was associated with Trail Making B (executive functions) decrease. • AD-RAI index and BrainAGE scores have limited but significant added value in predicting the subsequent cognitive decline in elderly controls when compared to the established visual MRI markers of brain aging, notably MTA, Fazekas score, and number of CMBs.
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3. |
- Kurth, Florian, et al.
(författare)
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Brain Sex in Transgender Women Is Shifted towards Gender Identity
- 2022
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Ingår i: Journal of Clinical Medicine. - : MDPI. - 2077-0383. ; 11:6
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Tidskriftsartikel (refereegranskat)abstract
- Transgender people report discomfort with their birth sex and a strong identification with the opposite sex. The current study was designed to shed further light on the question of whether the brains of transgender people resemble their birth sex or their gender identity. For this purpose, we analyzed a sample of 24 cisgender men, 24 cisgender women, and 24 transgender women before gender-affirming hormone therapy. We employed a recently developed multivariate classifier that yields a continuous probabilistic (rather than a binary) estimate for brains to be male or female. The brains of transgender women ranged between cisgender men and cisgender women (albeit still closer to cisgender men), and the differences to both cisgender men and to cisgender women were significant (p = 0.016 and p < 0.001, respectively). These findings add support to the notion that the underlying brain anatomy in transgender people is shifted away from their biological sex towards their gender identity.
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4. |
- Kurth, Florian, et al.
(författare)
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Preliminary evidence for a lower brain age in children with attention-deficit/hyperactivity disorder
- 2022
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Ingår i: Frontiers in Psychiatry. - : Frontiers Media S.A.. - 1664-0640. ; 13
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Tidskriftsartikel (refereegranskat)abstract
- Attention-deficit hyperactivity disorder (ADHD) is a debilitating disorder with apparent roots in abnormal brain development. Here, we quantified the level of individual brain maturation in children with ADHD using structural neuroimaging and a recently developed machine learning algorithm. More specifically, we compared the BrainAGE index between three groups matched for chronological age (mean +/- SD: 11.86 +/- 3.25 years): 89 children diagnosed with ADHD, 34 asymptomatic siblings of those children with ADHD, and 21 unrelated healthy control children. Brains of children with ADHD were estimated significantly younger (-0.85 years) than brains of healthy controls (Cohen's d = -0.33; p = 0.028, one-tailed), while there were no significant differences between unaffected siblings and healthy controls. In addition, more severe ADHD symptoms were significantly associated with younger appearing brains. Altogether, these results are in line with the proposed delay of individual brain maturation in children with ADHD. However, given the relatively small sample size (N = 144), the findings should be considered preliminary and need to be confirmed in future studies.
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5. |
- Luders, Eileen, et al.
(författare)
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Cortical gyrification in women and men and the (missing) link to prenatal androgens
- 2024
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Ingår i: European Journal of Neuroscience. - : John Wiley & Sons. - 0953-816X .- 1460-9568.
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Tidskriftsartikel (refereegranskat)abstract
- Previous studies have reported sex differences in cortical gyrification. Since most cortical folding is principally defined in utero, sex chromosomes as well as gonadal hormones are likely to influence sex-specific aspects of local gyrification. Classic congenital adrenal hyperplasia (CAH) causes high levels of androgens during gestation in females, whereas levels in males are largely within the typical male range. Therefore, CAH provides an opportunity to study the possible effects of prenatal androgens on cortical gyrification. Here, we examined the vertex-wise absolute mean curvature—a common estimate for cortical gyrification—in individuals with CAH (33 women and 20 men) and pair-wise matched controls (33 women and 20 men). There was no significant main effect of CAH and no significant CAH-by-sex interaction. However, there was a significant main effect of sex in five cortical regions, where gyrification was increased in women compared to men. These regions were located on the lateral surface of the brain, specifically left middle frontal (rostral and caudal), right inferior frontal, left inferior parietal, and right occipital. There was no cortical region where gyrification was increased in men compared to women. Our findings do not only confirm prior reports of increased cortical gyrification in female brains but also suggest that cortical gyrification is not significantly affected by prenatal androgen exposure. Instead, cortical gyrification might be determined by sex chromosomes either directly or indirectly—the latter potentially by affecting the underlying architecture of the cortex or the size of the intracranial cavity, which is smaller in women.
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6. |
- Luders, Eileen, et al.
(författare)
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Effects of Congenital Adrenal Hyperplasia (CAH) and Biological Sex on Brain Size
- 2024
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Ingår i: Anatomia. - Basel : MDPI. - 2813-0545. ; 3:3, s. 155-162
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Tidskriftsartikel (refereegranskat)abstract
- Congenital Adrenal Hyperplasia (CAH) has been reported to involve structural alterations in some brain regions. However, it remains to be established whether there is also an impact on the size of the brain as a whole. Here, we compiled the largest CAH sample to date (n = 53), matched pair-wise to a control group (n = 53) on sex, age, and verbal intelligence. Using T1-weighted brain scans, we calculated intracranial volume (ICV) as well as total brain volume (TBV), which are both common estimates for brain size. The statistical analysis was performed using a general linear model assessing the effects of CAH (CAH vs. controls), sex (women vs. men), and any CAH-by-sex interaction. The outcomes were comparable for ICV and TBV, i.e., there was no significant main effect of CAH and no significant CAH-by-sex interaction. However, there was a significant main effect of sex, with larger ICVs and TBVs in men than in women. Our findings contribute to an understudied field of research exploring brain anatomy in CAH. In contrast to some existing studies suggesting a smaller brain size in CAH, we did not observe such an effect. In other words, ICV and TBV in women and men with CAH did not differ significantly from those in controls. Notwithstanding, we observed the well-known sex difference in brain size (12.69% for ICV and 12.50% for TBV), with larger volumes in men than in women, which is in agreement with the existing literature.
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7. |
- Luders, Eileen, et al.
(författare)
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From baby brain to mommy brain : Widespread gray matter gain after giving birth
- 2020
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Ingår i: Cortex. - : ELSEVIER MASSON, CORP OFF. - 0010-9452 .- 1973-8102. ; 126, s. 334-342
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Tidskriftsartikel (refereegranskat)abstract
- Pregnancy results in obvious physiological changes to the female body, but data as to what happens to the maternal brain after giving birth are sparse as well as inconsistent. The overall goal of this study is to determine the nature of cerebral change in the postpartum period. For this purpose, we analyzed T1-weighted brain images of 14 healthy women (age range: 25-38 years) at two time points, specifically within 1-2 days of childbirth (immediate postpartum) and at 4-6 weeks after childbirth (late postpartum). When comparing voxel-wise gray matter between these two time points, there was no evidence of any significant decrease. Instead, we detected a pronounced gray matter increase involving both cortical and subcortical regions, such as the pre- and postcentral gyrus, the frontal and central operculum, the inferior frontal gyrus, the precuneus, and the middle occipital gyrus, as well as the thalamus and caudate. These structural changes occurring within only 4-6 weeks after delivery are reflective of a high degree of neuroplasticity and massive adaptations in the maternal brain. They may suggest a restoration of brain tissue following pregnancy and/or a substantial brain reorganization, possibly to accommodate a multifaceted repertoire of complex behaviors associated with being a mother.
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8. |
- Luders, Eileen, et al.
(författare)
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Gray matter increases within subregions of the hippocampal complex after pregnancy
- 2021
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Ingår i: Brain Imaging and Behavior. - : Springer Nature. - 1931-7557 .- 1931-7565. ; 15:6, s. 2790-2794
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Tidskriftsartikel (refereegranskat)abstract
- Neuroimaging findings - although still relatively sparse in the realm of postpartum research - suggest significant tissue increases within the hippocampus or its vicinity after giving birth. Given that the hippocampus is not a homogenous structure, effects may manifest differently across the hippocampal complex. Thus, the goal of this study was to determine the presence, magnitude, and direction of postpartum gray matter changes within five hippocampal subregions, specifically the dentate gyrus, the subiculum, and the subfields of the cornu ammonis (CA1, CA2 and CA3). For this purpose, we analyzed brain images of 14 healthy women acquired at immediate postpartum (within 1-2 days of childbirth) and at late postpartum (at 4-6 weeks after childbirth). Changes in hippocampal gray matter between both time points were calculated for all subregions as well as the hippocampal complex as a whole by integrating imaging-based intensity information with microscopically defined cytoarchitectonic probabilities. Hippocampal gray matter increased significantly within the right subiculum, right CA2, and right CA3. These findings may suggest that brain tissue lost during pregnancy is being restored after giving birth, perhaps even expanded compared to before pregnancy. Possible events on the microanatomical level include dendritic branching as well as the generation of new synapses, glia cells, and blood vessels. Altogether, the outcomes of our study confirm that hippocampal gray matter increases in the female human brain after giving birth, with differential effects across the hippocampal complex.
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9. |
- Luders, Eileen, et al.
(författare)
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Postpartum Gray Matter Changes in the Auditory Cortex
- 2021
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Ingår i: Journal of Clinical Medicine. - : MDPI. - 2077-0383. ; 10:23
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Tidskriftsartikel (refereegranskat)abstract
- After giving birth, a mother's brain undergoes functional adaptations fostering the ability to properly respond to the needs of her newborn. Tuning into and understanding her baby's crying is among the top skills required and executed in the early stages of motherhood. However, surprisingly little is known about potential changes in the anatomy of the maternal auditory cortex. Therefore, in this longitudinal study, we compared the brains of 14 healthy women between immediate postpartum (within 1-2 days of childbirth) and late postpartum (at 4-6 weeks after childbirth), focusing on areas of the primary, secondary, and higher auditory cortex. We observed significant volume increases within all auditory regions and subregions examined, which might reflect rapid adaptations of the mother's brain in relation to reliably interpreting her newborn's cries. There was also a trend for a larger postpartum increase within right-hemispheric regions compared to left-hemispheric regions that might be specifically linked to the ability to discern the pitch, sound, and volume of a baby's crying. Follow-up research is warranted to replicate these findings and evaluate their current interpretation.
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10. |
- Luders, Eileen, et al.
(författare)
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Potential Brain Age Reversal after Pregnancy : Younger Brains at 4–6 Weeks Postpartum
- 2018
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Ingår i: Neuroscience. - : Elsevier. - 0306-4522 .- 1873-7544. ; 386, s. 309-314
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Tidskriftsartikel (refereegranskat)abstract
- Pregnancy is accompanied by complex biological adaptations, including extreme hormonal fluctuations. Moreover, changes on the endocrine level are accompanied by changes in cerebral anatomy, such as reductions in brain or gray matter volume. Since declining brain and tissue volumes are characteristic for normal aging, the question arises of whether such pregnancy-induced anatomical effects are permanent or transient. To answer this question, we acquired high-resolution brain image data of 14 healthy women in their mid-twenties to late thirties at two time points: within 1–2 days of childbirth (early postpartum) and at 4–6 weeks after childbirth (late postpartum). At both time points, we estimated the brain ages for each woman using a well-validated machine learning approach based on pattern recognition. Ultimately, this algorithm – designed to identify anatomical correlates of age across the entire brain – reveals a single score for each individual: the BrainAGE index. Comparing the BrainAGE indices between both time points, female brains at late postpartum were estimated to be considerably younger than at early postpartum. On average, that difference was about five years (mean ± SD: 5.4 ± 2.4 years). These findings suggest a substantial restoration/rejuvenation effect after giving birth, which is evident already within the first couple of months.
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