Approximation of bone mineral density and subcutaneous adiposity using T1-weighted images of the human head.

Bones and brain are intricately connected and scientific interest in their interaction is growing. This has become particularly evident in the framework of clinical applications for various medical conditions, such as obesity and osteoporosis. The adverse effects of obesity on brain health have long been recognised, but few brain imaging studies provide sophisticated body composition measures. Here we propose to extract the following bone- and adiposity-related measures from T1-weighted MR images of the head: an approximation of skull bone mineral density (BMD), skull bone thickness, and two approximations of subcutaneous fat (i.e., the intensity and thickness of soft non-brain head tissue). The measures pertaining to skull BMD, skull bone thickness, and intensi-ty-based adiposity proxy proved to be reliable ( r =.93/.83/.74, p <.001) and valid, with high correlations to DXA-de-rived head BMD values (rho=.70, p <.001) and MRI-derived abdominal subcutaneous adipose volume (rho=.62, p <.001). Thickness-based adiposity proxy had only a low retest reliability ( r =.58, p <.001).The outcomes of this study constitute an important step towards extracting relevant non-brain features from available brain scans.

Corpus callosum morphology and relationships to illness phenotypes in individuals with anorexia nervosa.

Anorexia nervosa is an often-severe psychiatric illness characterized by significantly low body weight, fear of gaining weight, and distorted body image. Multiple neuroimaging studies have shown abnormalities in cortical morphology, mostly associated with the starvation state. Investigations of white matter, while more limited in number, have suggested global and regional volume reductions, as well as abnormal diffusivity in multiple regions including the corpus callosum. Yet, no study has specifically examined thickness of the corpus callosum, a large white matter tract instrumental in the inter-hemispheric integration of sensory, motor, and cognitive information. We analyzed MRI data from 48 adolescents and adults with anorexia nervosa and 50 healthy controls, all girls/women, to compare corpus callosum thickness and examined relationships with body mass index (BMI), illness duration, and eating disorder symptoms (controlling for BMI). There were no significant group differences in corpus callosum thickness. In the anorexia nervosa group, severity of body shape concerns was significantly, positively correlated with callosal thickness in the rostrum, genu, rostral body, isthmus, and splenium. In addition, there were significant positive correlations between eating disorder-related obsessions and compulsions and thickness of the anterior midbody, rostral body, and splenium. There were no significant associations between callosal thickness and BMI or illness duration. In sum, those with AN with worse concerns about bodily appearance and worse eating disorder-related obsessive thought patterns and compulsive behaviours have regionally thicker corpus callosum, independent of current weight status. These findings provide important neurobiological links to key, specific eating disorder behavioural phenotypes.

Cortical gyrification in women and men and the (missing) link to prenatal androgens.

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.

Reduced Age-Related Gray Matter Loss in the Orbitofrontal Cortex in Long-Term Meditators.

The orbitofrontal cortex (OFC) is a functionally heterogeneous brain region contributing to mental processes relating to meditation practices. The OFC has been reported to decline in volume with increasing age and differs in volume between meditation practitioners and non-practitioners. We hypothesized that the age-related decline of the OFC is diminished in meditation practitioners. We tested this hypothesis in a sample of 50 long-term meditators and 50 matched controls by correlating chronological age with regional gray matter volumes of the left and right OFC, as well as in seven left and right cytoarchitectonically defined subregions of the OFC (Fo1-Fo7). In both meditators and controls, we observed a negative relationship between age and OFC (sub)volumes, indicating that older participants have smaller OFC volumes. However, in meditators, the age-related decline was less steep compared to controls. These age-related differences reached significance for left and right Fo2, Fo3, Fo4, and Fo7, as well as left Fo5 and right Fo6. Since different subregions of the OFC are associated with distinct brain functions, further investigations are required to explore the functional implications of these findings in the context of meditation and the aging brain.

Cytoarchitectonically Defined Volumes of Early Extrastriate Visual Cortex in Unmedicated Adults With Body Dysmorphic Disorder.

BACKGROUND: Individuals with body dysmorphic disorder (BDD) misperceive that they have prominent defects in their appearance, resulting in preoccupations, time-consuming rituals, and distress. Previous neuroimaging studies have found abnormal activation patterns in the extrastriate visual cortex, which may underlie experiences of distorted perception of appearance. Correspondingly, we investigated gray matter volumes in individuals with BDD in the early extrastriate visual cortex using cytoarchitectonically defined maps that were previously derived from postmortem brains. METHODS: We analyzed T1-weighted magnetic resonance imaging data from 133 unmedicated male and female participants (BDD: n = 65; healthy control subjects: n = 68). We used cytoarchitectonically defined probability maps for the early extrastriate cortex, consisting of areas corresponding to V2, V3d, V3v/VP, V3a, and V4v. Gray matter volumes were compared between groups, supplemented by testing associations with clinical symptoms. RESULTS: The BDD group exhibited significantly larger gray matter volumes in the left and right early extrastriate cortex. Region-specific follow-up analyses revealed multiple subregions showing larger volumes in BDD, significant in the left V4v. There were no significant associations after corrections for multiple comparisons between gray matter volumes in early extrastriate cortex and BDD symptoms, comorbid symptoms, or duration of illness. CONCLUSIONS: Greater volumes of the early extrastriate visual cortex were evident in those with BDD, which aligns with outcomes of prior studies revealing BDD-specific functional abnormalities in these regions. Enlarged volumes of the extrastriate cortex in BDD might manifest during neurodevelopment, which could predispose individuals to aberrant visual perception and contribute to the core phenotype of distortion of perception for appearance.

Preliminary evidence for a lower brain age in children with attention-deficit/hyperactivity disorder.

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.

Preliminary evidence of links between ayahuasca use and the corpus callosum.

Background: Recent research suggests that ayahuasca and its alkaloid-containing ingredients may be helpful in the treatment and prevention of certain movement and neurodegenerative disorders. However, such research is still in its infancy and more studies in normative samples seem necessary to explore effects of ayahuasca on clinically relevant brain structures, such as the corpus callosum. Aims: The purpose of the present study was to investigate links between ayahuasca use and callosal structure in a normative sample. Methods: Using structural imaging data from 22 ayahuasca users and 22 matched controls we compared the thickness of the corpus callosum between both groups at 100 equidistant points across the entire midsagittal surface. In addition, we investigated point-wise correlations between callosal thickness and the number of past ayahuasca sessions. Results: The corpus callosum was significantly thicker within the isthmus in the ayahuasca group than in the control group. There was also a significant positive correlation between callosal thickness and the number of past ayahuasca sessions within the rostral body, albeit none of these effects survived corrections for multiple comparisons. No region was significantly thicker in the control than in the ayahuasca group, and no callosal region was negatively linked to ayahuasca use, even at uncorrected significance thresholds. Conclusion: This study provides preliminary evidence of links between ayahuasca use and the corpus callosum. However, future studies need to replicate these findings, preferably using larger sample sizes and ideally also utilizing longitudinal research designs, to draw any practical conclusion and offer implications for follow-up clinical research.

The neuroanatomy of pregnancy and postpartum.

Pregnancy and giving birth are exceptional states in a woman's life for many reasons. While the effects of pregnancy and childbirth on the female body are obvious, less is known about their impact on the female brain, especially in humans. The scientific literature is still sparse but we have identified 12 longitudinal neuroimaging studies conducted in women whose brains were scanned before pregnancy, during pregnancy, and/or after giving birth. This review summarizes and discusses the reported neuroanatomical changes during pregnancy, postpartum, and beyond. Some studies suggest that pregnancy is mainly associated with tissue decreases, and a few studies suggest that this tissue loss is mostly permanent. In contrast, the majority of studies seems to indicate that the postpartum period is accompanied by substantial tissue increases throughout the entire brain. Future research is clearly warranted to replicate and extend the current findings, while addressing various limitations and shortcomings of existing studies.

Aberrant callosal morphology in ex-smokers.

BACKGROUND: Cigarette smoking is associated with widespread structural alterations in both brain hemispheres as well as of the corpus callosum (i.e., the brain's main interhemispheric white matter pathway). While similar hemispheric alterations have also been reported in ex-smokers, no study has yet examined the corpus callosum in ex-smokers. METHODS: We compared callosal morphology in a sample of 107 ex-smokers (57 males/50 females) and 193 non-smokers (73 males/120 females), aged between 42 and 97 years. More specifically, we measured the total callosal area as well as seven callosal subregions using the Witelson parcellation scheme. RESULTS: At uncorrected levels, we detected significantly smaller callosal areas in ex-smokers than in non-smokers within the posterior midbody, genu, and isthmus (albeit the latter only on a trend level). When applying corrections for multiple comparisons, only the effect within the posterior midbody remained significant. CONCLUSIONS: Our findings suggest a weaker interhemispheric connectivity in ex-smokers compared to non-smokers, specifically between frontal and temporal areas.

Brain Sex in Transgender Women Is Shifted towards Gender Identity.

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.

Postpartum Gray Matter Changes in the Auditory Cortex.

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.

Optimal Blood Pressure Keeps Our Brains Younger.

Background: Elevated blood pressure (BP) is a major health risk factor and the leading global cause of premature death. Hypertension is also a risk factor for cognitive decline and dementia. However, when elevated blood pressure starts impacting cerebral health is less clear. We addressed this gap by estimating how a validated measure of brain health relates to changes in BP over a period of 12 years. Methods: Middle-age (44-46 years at baseline, n = 335, 52% female) and older-age (60-64 years, n = 351, 46% female) cognitively intact individuals underwent up to four brain scans. Brain health was assessed using a machine learning approach to produce an estimate of "observed" age (BrainAGE), which can be contrasted with chronological age. Longitudinal associations between blood pressures and BrainAGE were assessed with linear mixed-effects models. Results: A progressive increase in BP was observed over the follow up (MAP = 0.8 mmHg/year, SD = 0.92; SBP = 1.41 mmHg/year, SD = 1.49; DBP = 0.61 mmHg/year, SD = 0.78). In fully adjusted models, every additional 10 mmHg increase in blood pressure (above 90 for mean, 114 for systolic, and 74 for diastolic blood pressure) was associated with a higher BrainAGE by 65.7 days for mean, and 51.1 days for systolic/diastolic blood pressure. These effects occurred across the blood pressure range and were not exclusively driven by hypertension. Conclusion: Increasing blood pressure is associated with poorer brain health. Compared to a person becoming hypertensive, somebody with an ideal BP is predicted to have a brain that appears more than 6 months younger at midlife.

Reduced age-related gray matter loss in the subgenual cingulate cortex in long-term meditators.

Accumulating evidence suggests that meditation practices have positive effects on brain ageing overall. The cingulate is known to be recruited during meditation, but research into possible effects of meditation on the ageing of the cingulate is currently missing. Thus, the present study was designed to help close this knowledge gap, with particular focus on the subgenual cingulate, a region involved in emotional regulation and autonomic and endocrine functions, making it potentially relevant for meditation. Here, we investigated differences in age-related gray matter loss between 50 long-term meditation practitioners (28 male, 22 female), aged between 24 and 77, and 50 age- and sex-matched controls. Areas of interest were four subregions of the subgenual cingulate gyrus (areas 25, 33, s24, and s32) defined as per the Julich-Brain atlas. Our study revealed a significant age-related decline in all subregions in both meditators and controls, but with significantly lower rates of annual tissue loss in meditators, specifically in left and right area s32 and right area 25. These regions have been shown to play a role in mood regulation, autonomic processing, and the integration of emotion and cognitive processes, which are all involved in and impacted by meditation. Overall, the results add further evidence to the emerging notion that meditation may slow the effects of ageing on the brain.

Differential involvement of hippocampal subfields in Niemann-Pick type C disease: a case-control study.

Hippocampal brain regions are strongly implicated in Niemann Pick type C disease (NPC), but little is known regarding distinct subregions of the hippocampal complex and whether these are equally or differentially affected. To address this gap, we compared volumes of five hippocampal subfields between NPC and healthy individuals using MRI. To this end, 9 adult-onset NPC cases and 9 age- and gender-matched controls underwent a 3 T T1-weighted MRI scan. Gray matter volumes of the cornu ammonis (CA1, CA2 and CA3), dentate gyrus (DG), subiculum, entorhinal cortex and hippocampal-amygdalar transition area were calculated by integrating MRI-based image intensities with microscopically defined cytoarchitectonic probabilities. Compared to healthy controls, NPC patients showed smaller volumes of the CA1-3 and DG regions bilaterally, with the greatest difference localized to the left DG (Cohen's d = 1.993, p = 0.008). No significant associations were shown between hippocampal subfield volumes and key clinical features of NPC, including disease duration, symptom severity and psychosis. The pattern of hippocampal subregional atrophy in NPC differs from those seen in other dementias, which may indicate unique cytoarchitectural vulnerabilities in this earlier-onset disorder. Future MRI studies of hippocampal subfields may clarify its potential as a biomarker of neurodegeneration in NPC.

Significant increases of the amygdala between immediate and late postpartum: Pronounced effects within the superficial subregion.

Research exploring the underlying neuroanatomical correlates of early motherhood seems to suggest that the period after giving birth is marked by tissue increases in the mother's brain. While some studies point to the amygdala as one of the areas undergoing postpartum changes, existing analyses did not discriminate between the different subregions of this functionally heterogeneous structure. Thus, to further extend this understudied field of research and to better understand the potential role of the amygdala when transitioning to motherhood, we applied an advanced region-of-interest technique that enabled us to analyze the amygdala as a whole as well as its different subareas, specifically the left and right centromedian (CM), laterobasal (LB), and superficial (SF) regions. Comparing the brains of 14 healthy women between immediate postpartum (within 1-2 days of childbirth) and late postpartum (at 4-6 weeks after childbirth), we revealed increases of the amygdala. However, effects manifested differentially across subareas, with particularly strong effects for the SF region, moderate effects for the CM region, and no effects for the LB region. These findings might reflect region-specific adaptations of the mother's brain tuning into the distinct and ever-changing needs of a newborn, either as a cause for it or as a consequence thereof.

Corpus callosum morphology in major mental disorders: a magnetic resonance imaging study.

Mental disorders diagnosis is based on specific clinical criteria. However, clinical studies found similarities and overlapping phenomenology across a variety of disorders, which suggests a common neurobiological substrate. Thus, there is a need to measure disease-related neuroanatomical similarities and differences across conditions. While structural alterations of the corpus callosum have been investigated in obsessive-compulsive disorder, schizophrenia, major depressive disorder and bipolar disorder, no study has addressed callosal aberrations in all diseases in a single study. Moreover, results from pairwise comparisons (patients vs. controls) show some inconsistencies, possibly related to the parcellation methods to divide the corpus callosum into subregions. The main aim of the present paper was to uncover highly localized callosal characteristics for each condition (i.e. obsessive-compulsive disorder, schizophrenia, major depressive disorder and bipolar disorder) as compared either to healthy control subjects or to each other. For this purpose, we did not rely on any sub-callosal parcellation method, but applied a well-validated approach measuring callosal thickness at 100 equidistant locations along the whole midline of the corpus callosum. One hundred and twenty patients (30 in each disorder) as well as 30 controls were recruited for the study. All groups were closely matched for age and gender, and the analyses were performed controlling for the impact of antipsychotic treatment and illness duration. There was a significant main effect of group along the whole callosal surface. Pairwise post hoc comparisons revealed that, compared to controls, patients with obsessive-compulsive disorder had the thinnest corpora callosa with significant effects almost on the entire callosal structure. Patients with schizophrenia also showed thinner corpora callosa than controls but effects were confined to the isthmus and the anterior part of the splenium. No significant differences were found in both major depressive disorder and bipolar disorder patients compared to controls. When comparing the disease groups to each other, the corpus callosum was thinner in obsessive-compulsive disorder patients than in any other group. The effect was evident across the entire corpus callosum, with the exception of the posterior body. Altogether, our study suggests that the corpus callosum is highly changed in obsessive-compulsive disorder, selectively changed in schizophrenia and not changed in bipolar disorder and major depressive disorder. These results shed light on callosal similarities and differences among mental disorders providing valuable insights regarding the involvement of the major brain commissural fibre tract in the pathophysiology of each specific mental illness.

The Neuroanatomy of Transgender Identity: Mega-Analytic Findings From the ENIGMA Transgender Persons Working Group.

BACKGROUND: In contrast to cisgender persons, transgender persons identify with a different gender than the one assigned at birth. Although research on the underlying neurobiology of transgender persons has been accumulating over the years, neuroimaging studies in this relatively rare population are often based on very small samples resulting in discrepant findings. AIM: To examine the neurobiology of transgender persons in a large sample. METHODS: Using a mega-analytic approach, structural MRI data of 803 non-hormonally treated transgender men (TM, n = 214, female assigned at birth with male gender identity), transgender women (TW, n = 172, male assigned at birth with female gender identity), cisgender men (CM, n = 221, male assigned at birth with male gender identity) and cisgender women (CW, n = 196, female assigned at birth with female gender identity) were analyzed. OUTCOMES: Structural brain measures, including grey matter volume, cortical surface area, and cortical thickness. RESULTS: Transgender persons differed significantly from cisgender persons with respect to (sub)cortical brain volumes and surface area, but not cortical thickness. Contrasting the 4 groups (TM, TW, CM, and CW), we observed a variety of patterns that not only depended on the direction of gender identity (towards male or towards female) but also on the brain measure as well as the brain region examined. CLINICAL TRANSLATION: The outcomes of this large-scale study may provide a normative framework that may become useful in clinical studies. STRENGTHS AND LIMITATIONS: While this is the largest study of MRI data in transgender persons to date, the analyses conducted were governed (and restricted) by the type of data collected across all participating sites. CONCLUSION: Rather than being merely shifted towards either end of the male-female spectrum, transgender persons seem to present with their own unique brain phenotype. Mueller SC, Guillamon A, Zubiaurre-Elorza L, et al. The Neuroanatomy of Transgender Identity: Mega-Analytic Findings From the ENIGMA Transgender Persons Working Group. J Sex Med 2021;18:1122-1129.

Diminished Age-Related Decline of the Amygdala in Long-Term Meditation Practitioners.

OBJECTIVE: A growing body of scientific evidence suggests that meditation may slow brain aging. The amygdala-a heterogenous brain region known to decrease in volume with increasing age-seems to be involved in meditation and affected by meditation. Thus, we hypothesized that the age-related decline of the amygdala is diminished in meditation practitioners. METHODS: We investigated whether correlations between age and gray matter volumes of the amygdala are significantly reduced in 50 long-term meditators compared with 50 sex- and age-matched healthy controls. Both the meditator and control groups included 44% women. The age of the participants ranged between 24 and 77 years, with mean (standard deviation) ages of 50.4 (±11.8) years in meditators and 51.4 (±12.8) years in controls. In addition to studying the amygdala as a whole, we investigated its centromedial, laterobasal, and superficial subregions using a well-validated approach combining imaging-based signal intensities and cytoarchitectonically defined probabilities. RESULTS: We detected significant group-by-age interactions for the whole amygdala and for its subregions. Follow-up analyses indicated negative age-related correlations in both meditators and controls (the older the participants, the smaller the volumes) but with significantly steeper aging trajectories in controls. CONCLUSIONS: Altogether, these findings suggest that the age-related volume loss of the amygdala is less pronounced in long-term meditators. This effect was particularly evident for the laterobasal subregion, which has been functionally linked to aspects of self-focused reflection.

Gray matter increases within subregions of the hippocampal complex after pregnancy.

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.

The impact of aging on the subregions of the fusiform gyrus in healthy older adults.

The fusiform gyrus is known to decrease in size with increasing age. However, reported findings are inconsistent and existing studies differ in terms of the cohorts examined and/or the methods applied. Here, we analyzed age-related links in four distinct subregions of the fusiform gyrus through integrating imaging-based intensity information with microscopically defined cytoarchitectonic probabilities. In addition to age effects we investigated sex effects as well as age-by-sex interactions in a relatively large sample of 468 healthy subjects (272 females/196 males) covering a broad age range (42-97 years). We observed significant negative correlations between age and all four subregions of the fusiform gyrus indicating volume decreases over time, albeit with subregion-specific trajectories. Additionally, we observed significant negative quadratic associations with age for some subregions, suggesting an accelerating volume loss over time. These findings may serve as a frame of reference for future cross-sectional as well as longitudinal studies, not only for normative samples but also potentially for clinical conditions that present with abnormal atrophy of the fusiform gyrus. We did not detect any significant sex differences or sex-by-age interactions, suggesting that the size of the fusiform gyrus is similar in male and female brains and that age-related atrophy follows a similar trajectory in both men and women.