The topology of higher-order complexes associated with brain hubs in human connectomes.

Higher-order connectivity in complex systems described by simplexes of different orders provides a geometry for simplex-based dynamical variables and interactions. Simplicial complexes that constitute a functional geometry of the human connectome can be crucial for the brain complex dynamics. In this context, the best-connected brain areas, designated as hub nodes, play a central role in supporting integrated brain function. Here, we study the structure of simplicial complexes attached to eight global hubs in the female and male connectomes and identify the core networks among the affected brain regions. These eight hubs (Putamen, Caudate, Hippocampus and Thalamus-Proper in the left and right cerebral hemisphere) are the highest-ranking according to their topological dimension, defined as the number of simplexes of all orders in which the node participates. Furthermore, we analyse the weight-dependent heterogeneity of simplexes. We demonstrate changes in the structure of identified core networks and topological entropy when the threshold weight is gradually increased. These results highlight the role of higher-order interactions in human brain networks and provide additional evidence for (dis)similarity between the female and male connectomes.

Role of T1 mapping to evaluate brain aging in a healthy population.

PURPOSE: To investigate the relationship between healthy brain aging and T1 relaxation time obtained by T1 mapping. MATERIALS AND METHODS: A total of 211 (102 males, 109 females; age range: 20-89 years; mean age: 54 years) healthy volunteers underwent T1 mapping between July 2018 and January 2019. Regions of interest (ROIs) were placed on T1 maps in different anatomical regions, including the thalamus, putamen, globus pallidus, head of the caudate nucleus, nucleus accumbens, genu of the corpus callosum, and frontal lobe white matter (WM). Additionally, linear and quadratic regression analyses of ROIs were performed. RESULTS: There were significant quadratic and negative linear correlations between T1 relaxation times in the thalamus, putamen, and age (p < .001). Although the nucleus accumbens did not show a significant relationship between T1 relaxation times and age by linear regression (p = .624), a statistically significant relationship was obtained by quadratic regression (p < .001). For the globus pallidus, head of the caudate nucleus, genu of the corpus callosum and frontal lobe WM the quadratic regression analysis showed a better relationship than the linear correlation analysis. CONCLUSION: Age-related changes in T1 relaxation time vary by location in GM and WM.

Quantification of Microsurgical Anatomy in Three-Dimensional Model: Transfrontal Approach for Anterior Portion of the Thalamus.

The thalamus located in the deep site of cerebrum with the risk of internal capsule injury during operation. The purpose of this study was to compare the anatomy for exposure and injury using simulative surgical corridor of 3-dimensional model. The 3-dimensional anatomy model of thalamus in cerebrum was created based on magnetic resonance imaging performed for 15 patients with trigeminal neuralgia. The midpoint of line between anterior edge and top of thalamus was the target exposed. Axis connecting the target with the anterior edge and top of caudate head was used to outline the cylinder, respectively, simulating surgical corridors 1 and 2 of transfrontal approach. Cerebral tissues involved in the corridors were observed, measured, and compared. Incision of cortex was made on the anterior portion of inferior frontal gyrus through corridor 1 and middle frontal gyrus through corridor 2. Both of the 2 corridors passed the caudate nucleus, the anterior limb and genu of internal capsule, ultimately reached the upper anterior portion of thalamus. The volumes of white matter, caudate head, and thalamus in the corridor 1 were more than those in corridor 2. Conversely, the volumes of cortex, internal capsule in corridor 2 were more than those in corridor 1. In conclusion, surgical anatomy-specific volume is helpful to postulate the intraoperative injury of transfrontal approach exposing anterior portion of the thalamus. The detailed information in the quantification of microsurgical anatomy will be used to develop minimally invasive operation.

Shape-related characteristics of age-related differences in subcortical structures.

OBJECTIVES: With an increasing aging population, it is important to understand biological markers of aging. Subcortical volume is known to differ with age; additionally considering shape-related characteristics may provide a better index of age-related differences. Fractal dimensionality is more sensitive to age-related differences, but is borne out of mathematical principles, rather than neurobiological relevance. We considered four distinct measures of shape and how they relate to aging and fractal dimensionality: surface-to-volume ratio, sphericity, long-axis curvature, and surface texture. METHODS: Structural MRIs from a combined sample of over 600 healthy adults were used to measure age-related differences in the structure of the thalamus, putamen, caudate, and hippocampus. For each, volume and fractal dimensionality were calculated, as well as four distinct shape measures. These measures were examined for their utility in explaining age-related variability in brain structure. RESULTS: The four shape measures were able to account for 80%-90% of the variance in fractal dimensionality. Of the distinct shape measures, surface-to-volume ratio was the most sensitive biomarker. CONCLUSION: Though volume is often used to characterize inter-individual differences in subcortical structures, our results demonstrate that additional measures can be useful complements. Our results indicate that shape characteristics are useful biological markers of aging.

Microsurgical anatomy of the central core of the brain.

OBJECTIVE The purpose of this study was to describe in detail the cortical and subcortical anatomy of the central core of the brain, defining its limits, with particular attention to the topography and relationships of the thalamus, basal ganglia, and related white matter pathways and vessels. METHODS The authors studied 19 cerebral hemispheres. The vascular systems of all of the specimens were injected with colored silicone, and the specimens were then frozen for at least 1 month to facilitate identification of individual fiber tracts. The dissections were performed in a stepwise manner, locating each gray matter nucleus and white matter pathway at different depths inside the central core. The course of fiber pathways was also noted in relation to the insular limiting sulci. RESULTS The insular surface is the most superficial aspect of the central core and is divided by a central sulcus into an anterior portion, usually containing 3 short gyri, and a posterior portion, with 2 long gyri. It is bounded by the anterior limiting sulcus, the superior limiting sulcus, and the inferior limiting sulcus. The extreme capsule is directly underneath the insular surface and is composed of short association fibers that extend toward all the opercula. The claustrum lies deep to the extreme capsule, and the external capsule is found medial to it. Three fiber pathways contribute to form both the extreme and external capsules, and they lie in a sequential anteroposterior disposition: the uncinate fascicle, the inferior fronto-occipital fascicle, and claustrocortical fibers. The putamen and the globus pallidus are between the external capsule, laterally, and the internal capsule, medially. The internal capsule is present medial to almost all insular limiting sulci and most of the insular surface, but not to their most anteroinferior portions. This anteroinferior portion of the central core has a more complex anatomy and is distinguished in this paper as the "anterior perforated substance region." The caudate nucleus and thalamus lie medial to the internal capsule, as the most medial structures of the central core. While the anterior half of the central core is related to the head of the caudate nucleus, the posterior half is related to the thalamus, and hence to each associated portion of the internal capsule between these structures and the insular surface. The central core stands on top of the brainstem. The brainstem and central core are connected by several white matter pathways and are not separated from each other by any natural division. The authors propose a subdivision of the central core into quadrants and describe each in detail. The functional importance of each structure is highlighted, and surgical approaches are suggested for each quadrant of the central core. CONCLUSIONS As a general rule, the internal capsule and its vascularization should be seen as a parasagittal barrier with great functional importance. This is of particular importance in choosing surgical approaches within this region.

Immersive bilingualism reshapes the core of the brain.

Bilingualism has been shown to affect the structure of the brain, including cortical regions related to language. Less is known about subcortical structures, such as the basal ganglia, which underlie speech monitoring and language selection, processes that are crucial for bilinguals, as well as other linguistic functions, such as grammatical and phonological acquisition and processing. Simultaneous bilinguals have demonstrated significant reshaping of the basal ganglia and the thalamus compared to monolinguals. However, it is not clear whether these effects are due to learning of the second language (L2) at a very young age or simply due to continuous usage of two languages. Here, we show that bilingualism-induced subcortical effects are directly related to the amount of continuous L2 usage, or L2 immersion. We found significant subcortical reshaping in non-simultaneous (or sequential) bilinguals with extensive immersion in a bilingual environment, closely mirroring the recent findings in simultaneous bilinguals. Importantly, some of these effects were positively correlated to the amount of L2 immersion. Conversely, sequential bilinguals with comparable proficiency and age of acquisition (AoA) but limited immersion did not show similar effects. Our results provide structural evidence to suggestions that L2 acquisition continuously occurs in an immersive environment, and is expressed as dynamic reshaping of the core of the brain. These findings propose that second language learning in the brain is a dynamic procedure which depends on active and continuous L2 usage.

Heritability of the shape of subcortical brain structures in the general population.

The volumes of subcortical brain structures are highly heritable, but genetic underpinnings of their shape remain relatively obscure. Here we determine the relative contribution of genetic factors to individual variation in the shape of seven bilateral subcortical structures: the nucleus accumbens, amygdala, caudate, hippocampus, pallidum, putamen and thalamus. In 3,686 unrelated individuals aged between 45 and 98 years, brain magnetic resonance imaging and genotyping was performed. The maximal heritability of shape varies from 32.7 to 53.3% across the subcortical structures. Genetic contributions to shape extend beyond influences on intracranial volume and the gross volume of the respective structure. The regional variance in heritability was related to the reliability of the measurements, but could not be accounted for by technical factors only. These findings could be replicated in an independent sample of 1,040 twins. Differences in genetic contributions within a single region reveal the value of refined brain maps to appreciate the genetic complexity of brain structures.

Susceptibility-Weighted Imaging of the Anatomic Variation of Thalamostriate Vein and Its Tributaries.

BACKGROUND AND PURPOSE: Thalamostriate vein (TSV) is an important tributary of the internal cerebral vein, which mainly drains the basal ganglia and deep medulla. The purpose of this study was to explore the anatomic variation and quality of TSV and its smaller tributaries using susceptibility-weighted imaging (SWI). METHODS: We acquired SWI images in 40 volunteers on a 3.0T MR system using an 8-channel high-resolution phased array coil. The frequencies of the TSV and its tributaries were evaluated. We classified TSV into types I (forming a venous angle) and II (forming a false venous angle). We classified anterior caudate vein (ACV)into types 1 (1 trunk) and 2 (2 trunks) as well as into types A (joiningTSV), B (joining anterior septal vein), and C (joining the angle of both veins). RESULTS: The TSV drains the areas of caudate nucleus, internal capsule,lentiform nucleus, external capsule, claustrum, extreme capsule and the white matter of the frontoparietal lobes,except thalamus. The frequencies of the TSV, ACV and transverse caudate vein (ACV) were 92.5%, 87.5% and 63.8%, respectively. We found TSV types I and II in 79.7%, and 20.3% with significantly different constitution ratios (P< 0.05). The most common types of ACV were type 1 (90.0%) and type A (64.3%). CONCLUSION: The complex three-dimensional (3D) venous architecture of TSV and its small tributaries manifests great variation, with significant and practical implications for neurosurgery.

Developmentally stable whole-brain volume reductions and developmentally sensitive caudate and putamen volume alterations in those with attention-deficit/hyperactivity disorder and their unaffected siblings.

IMPORTANCE: Attention-deficit/hyperactivity disorder (ADHD) is a heritable neurodevelopmental disorder. It has been linked to reductions in total brain volume and subcortical abnormalities. However, owing to heterogeneity within and between studies and limited sample sizes, findings on the neuroanatomical substrates of ADHD have shown considerable variability. Moreover, it remains unclear whether neuroanatomical alterations linked to ADHD are also present in the unaffected siblings of those with ADHD. OBJECTIVE: To examine whether ADHD is linked to alterations in whole-brain and subcortical volumes and to study familial underpinnings of brain volumetric alterations in ADHD. DESIGN, SETTING, AND PARTICIPANTS: In this cross-sectional study, we included participants from the large and carefully phenotyped Dutch NeuroIMAGE sample (collected from September 2009-December 2012) consisting of 307 participants with ADHD, 169 of their unaffected siblings, and 196 typically developing control individuals (mean age, 17.21 years; age range, 8-30 years). MAIN OUTCOMES AND MEASURES: Whole-brain volumes (total brain and gray and white matter volumes) and volumes of subcortical regions (nucleus accumbens, amygdala, caudate nucleus, globus pallidus, hippocampus, putamen, thalamus, and brainstem) were derived from structural magnetic resonance imaging scans using automated tissue segmentation. RESULTS: Regression analyses revealed that relative to control individuals, participants with ADHD had a 2.5% smaller total brain (ß = -31.92; 95% CI, -52.69 to -11.16; P = .0027) and a 3% smaller total gray matter volume (ß = -22.51; 95% CI, -35.07 to -9.96; P = .0005), while total white matter volume was unaltered (ß = -10.10; 95% CI, -20.73 to 0.53; P = .06). Unaffected siblings had total brain and total gray matter volumes intermediate to participants with ADHD and control individuals. Significant age-by-diagnosis interactions showed that older age was linked to smaller caudate (P < .001) and putamen (P = .01) volumes (both corrected for total brain volume) in control individuals, whereas age was unrelated to these volumes in participants with ADHD and their unaffected siblings. Attention-deficit/hyperactivity disorder was not significantly related to the other subcortical volumes. CONCLUSIONS AND RELEVANCE: Global differences in gray matter volume may be due to alterations in the general mechanisms underlying normal brain development in ADHD. The age-by-diagnosis interaction in the caudate and putamen supports the relevance of different brain developmental trajectories in participants with ADHD vs control individuals and supports the role of subcortical basal ganglia alterations in the pathophysiology of ADHD. Alterations in total gray matter and caudate and putamen volumes in unaffected siblings suggest that these volumes are linked to familial risk for ADHD.

Functional network mirrored in the prefrontal cortex, caudate nucleus, and thalamus: high-resolution functional imaging and structural connectivity.

Despite myriads of studies on a parallel organization of cortico-striatal-thalamo-cortical loops, direct evidence of this has been lacking for the healthy human brain. Here, we scrutinize the functional specificity of the cortico-subcortical loops depending on varying levels of cognitive hierarchy as well as their structural connectivity with high-resolution fMRI and diffusion-weighted MRI (dMRI) at 7 tesla. Three levels of cognitive hierarchy were implemented in two domains: second language and nonlanguage. In fMRI, for the higher level, activations were found in the ventroanterior portion of the prefrontal cortex (PFC), the head of the caudate nucleus (CN), and the ventral anterior nucleus (VA) in the thalamus. Conversely, for the lower level, activations were located in the posterior region of the PFC, the body of the CN, and the medial dorsal nucleus (MD) in the thalamus. This gradient pattern of activations was furthermore shown to be tenable by the parallel connectivity in dMRI tractography connecting the anterior regions of the PFC with the head of the CN and the VA in the thalamus, whereas the posterior activations of the PFC were linked to the body of the CN and the MD in the thalamus. This is the first human in vivo study combining fMRI and dMRI showing that the functional specificity is mirrored within the cortico-subcortical loop substantiated by parallel networks.

Dispositional mindfulness co-varies with smaller amygdala and caudate volumes in community adults.

Mindfulness, a psychological process reflecting attention and awareness to what is happening in the present moment, has been associated with increased well-being and decreased depression and anxiety in both healthy and patient populations. However, little research has explored underlying neural pathways. Recent work suggests that mindfulness (and mindfulness training interventions) may foster neuroplastic changes in cortico-limbic circuits responsible for stress and emotion regulation. Building on this work, we hypothesized that higher levels of dispositional mindfulness would be associated with decreased grey matter volume in the amgydala. In the present study, a self-report measure of dispositional mindfulness and structural MRI images were obtained from 155 healthy community adults. Volumetric analyses showed that higher dispositional mindfulness is associated with decreased grey matter volume in the right amygdala, and exploratory analyses revealed that higher dispositional mindfulness is also associated with decreased grey matter volume in the left caudate. Moreover, secondary analyses indicate that these amygdala and caudate volume associations persist after controlling for relevant demographic and individual difference factors (i.e., age, total grey matter volume, neuroticism, depression). Such volumetric differences may help explain why mindful individuals have reduced stress reactivity, and suggest new candidate structural neurobiological pathways linking mindfulness with mental and physical health outcomes.

Subcortical surgical anatomy of the lateral frontal region: human white matter dissection and correlations with functional insights provided by intraoperative direct brain stimulation: laboratory investigation.

OBJECT: Recent neuroimaging and surgical results support the crucial role of white matter in mediating motor and higher-level processing within the frontal lobe, while suggesting the limited compensatory capacity after damage to subcortical structures. Consequently, an accurate knowledge of the anatomofunctional organization of the pathways running within this region is mandatory for planning safe and effective surgical approaches to different diseases. The aim of this dissection study was to improve the neurosurgeon's awareness of the subcortical anatomofunctional architecture for a lateral approach to the frontal region, to optimize both resection and postoperative outcome. METHODS: Ten human hemispheres (5 left, 5 right) were dissected according to the Klingler technique. Proceeding lateromedially, the main association and projection tracts as well as the deeper basal structures were identified. The authors describe the anatomy and the relationships among the exposed structures in both a systematic and topographical surgical perspective. Structural results were also correlated to the functional responses obtained during resections of infiltrative frontal tumors guided by direct cortico-subcortical electrostimulation with patients in the awake condition. RESULTS: The eloquent boundaries crucial for a safe frontal lobectomy or an extensive lesionectomy are as follows: 1) the motor cortex; 2) the pyramidal tract and premotor fibers in the posterior and posteromedial part of the surgical field; 3) the inferior frontooccipital fascicle and the superior longitudinal fascicle posterolaterally; and 4) underneath the inferior frontal gyrus, the head of the caudate nucleus, and the tip of the frontal horn of the lateral ventricle in the depth. CONCLUSIONS: Optimization of results following brain surgery, especially within the frontal lobe, requires a perfect knowledge of functional anatomy, not only at the cortical level but also with regard to subcortical white matter connectivity.

Performance-based connectivity analysis: a path to convergence with clinical studies.

Connectivity analyses have become increasingly important in functional imaging. When used to describe the functional anatomy of a specific behavior, these analyses are generally applied to a subset of the data that demonstrate significant differences when experimental conditions are contrasted. Such data reduction is sub-optimal for a systems approach as it assumes that all data that survive the statistical contrast filter are related to the behavior and that none of the filtered data has a significant function. When such data filtering is applied to speech and language tasks, the resulting functional anatomy rarely reflects the brain lateralization established in over a century and a half of clinical studies. A two-step performance-based connectivity analysis is described in which the first step uses multiple linear regression to establish a direct relationship between regional brain activity and a measure of performance. The second step uses partial correlations to examine the functional relationships between the predictor regions and other brain regions. When applied to regional cerebral blood flow data obtained with positron emission tomography during a speech production task, the results demonstrate left lateralization of motor control areas, thalamic involvement in repetition rate, and auditory cortical suppression, all consistent with clinical observations. The integration of performance measures into the earliest stages of image analysis without reliance on data filtering based on decomposition may provide a path toward convergence with traditional descriptions of functional anatomy based on clinical studies.

Anatomical connectivity between subcortical structures.

Understanding anatomical connectivity is crucial for improving outcomes of deep brain stimulation surgery. Tractography is a promising method for noninvasively investigating anatomical connectivity, but connections between subcortical regions have not been closely examined by this method. As many connections to subcortical regions converge at the internal capsule (IC), we investigate the connectivity through the IC to three subcortical nuclei (caudate, lentiform nucleus, and thalamus) in six macaques. We show that a statistical correction for a known distance-related artifact in tractography results in large changes in connectivity patterns. Our results suggest that care should be taken in using tractography to assess anatomical connectivity between subcortical structures.

Longitudinal evidence for diminished frontal cortex function in aging.

Cross-sectional estimates of age-related changes in brain structure and function were compared with 6-y longitudinal estimates. The results indicated increased sensitivity of the longitudinal approach as well as qualitative differences. Critically, the cross-sectional analyses were suggestive of age-related frontal overrecruitment, whereas the longitudinal analyses revealed frontal underrecruitment with advancing age. The cross-sectional observation of overrecruitment reflected a select elderly sample. However, when followed over time, this sample showed reduced frontal recruitment. These findings dispute inferences of true age changes on the basis of age differences, hence challenging some contemporary models of neurocognitive aging, and demonstrate age-related decline in frontal brain volume as well as functional response.

Feasibility of prefronto-caudate pathway tractography using high resolution diffusion tensor tractography data at 3T.

Mapping the human brain frontostriatal pathways using noninvasive diffusion tensor imaging (DTI) has been hampered by the inadequate imaging sensitivity, poor spatial resolution, lower tensor anisotropy within gray matter, increased partial volume averaging effects and poor signal-to-noise ratio. We investigated for the first time the utility of high spatial resolution DTI-based fiber-tractography using the fiber assignment by continuous tracking (FACT) to reconstruct and quantify bilaterally the prefronto-caudo-thalamic connections within the human brain at 3T. Five healthy right-handed men (age range 24-37 years) were studied. We traced the anterior thalamic radiation and prefronto-caudo-thalamic pathways bilaterally and measured the volume of each tract and the corresponding diffusion tensor metrics in all subjects. The anterior thalamic radiation tract volume and corresponding fractional anisotropy (FA) were significantly larger bilaterally than prefronto-caudate pathway, whereas the mean diffusivity (D(av)) values were similar (p>0.7). For both anterior thalamic radiation and prefronto-caudate pathway the tract volume and corresponding DTI metrics (FA, D(av)) were not significantly different between the two hemispheres (p>0.2). Our DTI acquisition protocol and analysis permitted the reconstruction of the connectivity of the caudate with the thalamus as well as with the prefrontal cortex and allowed tracking of the whole trajectory of the prefronto-caudo-thalamic pathway.

On emotional conflict: interference resolution of happy and angry prosody reveals valence-specific effects.

To comprehend emotional prosodic cues in speech is a critical function of human social life. However, it is common in everyday communication that conflicting information in emotional prosody and semantic content co-occur. Here, we sought to specify brain regions involved in conflict monitoring of these interfering communication channels. By means of functional magnetic resonance imaging, we obtained signal increases in the right dorsal anterior cingulate cortex and right superior temporal gyrus (STG) and superior temporal sulcus when participants listened to incongruous compared with congruous sentences. Moreover, valence-specific effects were found in the left inferior frontal gyrus and left STG for happily intoned sentences expressing a negative content. The left caudate nucleus along with the thalamus was active when angrily intoned sentences were coupled with positive semantic content. Our results suggest a brain network that monitors conflict in emotional prosody and emotional semantic content comprising of medial prefrontal areas that have previously been associated with cognitive conflict processing. Furthermore, our study extends the knowledge of these processes by suggesting valence-specific differences of emotional conflict processing.

Overlap of nigrothalamic terminals and thalamostriatal neurons in the feline lateralis medialis-suprageniculate nucleus.

The lateralis medialis-suprageniculate nucleus (LM-Sg) of the feline posterior thalamus is a relay nucleus with a clear visuomotor function. In this study, we examined the distribution of axon terminals of the nigral afferent to the LM-Sg following injection of an anterograde tracer, biocytin, into the substantia nigra pars reticulata, and the distribution of the thalamostriatal projection neurons in the LM-Sg following the injection of wheat germ agglutinin conjugated with horseradish peroxidase (WGA-HRP) as a retrograde tracer into the caudate nucleus. The biocytin-labeled terminal-like puncta were located in the ventromedial portion of this nucleus in such a way that most of the labeled elements took the form of swellings having boutons in places, while a minority appeared in clusters of 3-5 large terminal-like puncta. The retrograde WGA-HRP-labeled neurons were also found in the ventromedial part of the LM-Sg, and the distributions of labeled nigrothalamic axon terminals and labeled thalamostriatal projection neurons therefore overlapped in this region. The present results indicate that the nigral afferent may make synaptic contacts directly with the thalamostriatal projection neurons within the LM-Sg.

Reduced caudate gray matter volume in women with major depressive disorder.

Previous brain-imaging studies have reported that major depressive disorder (MDD) is characterized by decreased volumes of several cortical and subcortical structures, including the hippocampus, amygdala, anterior cingulate cortex, and caudate nucleus. The purpose of the present study was to identify structural volumetric differences between MDD and healthy participants using a method that allows a comparison of gray and white matter volume across the whole brain. In addition, we explored the relation between symptom severity and brain regions with decreased volumes in MDD participants. The study group comprised 22 women diagnosed with MDD and 25 healthy women with no history of major psychiatric disorders. Magnetic resonance brain images were analyzed using optimized voxel-based morphometry to examine group differences in regional gray and white matter volume. Compared with healthy controls, MDD participants were found to have decreased gray matter volume in the bilateral caudate nucleus and the thalamus. No group differences were found for white matter volume, nor were there significant correlations between gray matter volumes and symptom severity within the MDD group. The present results suggest that smaller volume of the caudate nucleus may be related to the pathophysiology of MDD and may account for abnormalities of the cortico-striatal-pallido-thalamic loop in MDD.

Volumes, spatial extents and a probabilistic atlas of the human basal ganglia and thalamus.

The basal ganglia and thalamus are involved in processing all physiological behaviors and affected by many diseases. Accurate localization is a crucial issue in neuroimaging, particularly when working with groups of normalized images in a standard stereotaxic space. Here, manual delineation of the central structures (thalamus; nucleus caudatus and accumbens; putamen, pallidum, substantia nigra) was performed on 30 high resolution MRIs of healthy young adults (15 female, median age 31 years) in native space. Protocol inter-rater reliabilities were quantified as structure overlap (similarity indices, SIs). Structural volumes were calculated in native space, and after spatial normalization to stereotaxic space (MNI/ICBM152) and in relation to hemispheric volumes. Spatial extents relative to the anterior commissure (AC) were extracted. The 30 resulting atlases were then used to create probabilistic maps in stereotaxic space. Inter-rater SIs were high at 0.85-0.92 except for the nucleus accumbens. In native space, caudate, nucleus accumbens and putamen were significantly larger on the left, and the globus pallidus larger in males. After normalizing for brain volume, the nucleus accumbens, putamen and thalamus were larger on the left, with the gender difference in the globus pallidus still detectable. Some of these volume differences translated into significantly different distances from the AC. The probabilistic maps showed that overall the central structures' boundaries are relatively unchanged after spatial normalization. We present a comprehensive assessment of thalamic and basal ganglia volumetric and geometric data in both native and stereotaxic spaces. Probabilistic maps in MNI/ICBM152 space will allow accurate localization in group analyses.