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1.
BMC Neurosci ; 22(1): 30, 2021 04 26.
Artigo em Inglês | MEDLINE | ID: mdl-33902437

RESUMO

BACKGROUND: In everyday life, negative emotions can be implicitly regulated by positive stimuli, without any conscious cognitive engagement; however, the effects of such implicit regulation on mood and related neuro-mechanisms, remain poorly investigated in literature. Yet, improving implicit emotional regulation could reduce psychological burden and therefore be clinically relevant for treating psychiatric disorders with strong affective symptomatology. RESULTS: Music training reduced the negative emotional state elicited by negative odours. However, such change was not reflected at the brain level. CONCLUSIONS: In a context of affective rivalry a musical training enhances implicit regulatory processes. Our findings offer a first base for future studies on implicit emotion regulation in clinical populations.


Assuntos
Encéfalo/fisiologia , Regulação Emocional/fisiologia , Musicoterapia , Adulto , Feminino , Humanos , Masculino
2.
Brain Struct Funct ; 223(9): 4153-4168, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30187191

RESUMO

Robust spatial alignment of post mortem data and in vivo MRI acquisitions from different ages, especially from the early developmental stages, into standard spaces is still a bottleneck hampering easy comparison with the mainstream neuroimaging results. In this paper, we test a landmark-based spatial normalization strategy as a framework for the seamless integration of any macroscopic dataset in the context of the Human Brain Project (HBP). This strategy stems from an approach called DISCO embedding sulcal constraints in a registration framework used to initialize DARTEL, the widely used spatial normalization approach proposed in the SPM software. We show that this strategy is efficient with a heterogeneous dataset including challenging data as preterm newborns, infants, post mortem histological data and a synthetic atlas computed from averaging the ICBM database, as well as more commonly studied data acquired in vivo in adults. We then describe some perspectives for a research program aiming at improving folding pattern matching for atlas inference in the context of the future HBP's portal.


Assuntos
Encéfalo/anatomia & histologia , Processamento de Imagem Assistida por Computador , Imageamento por Ressonância Magnética/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Algoritmos , Atlas como Assunto , Bases de Dados Factuais , Humanos , Recém-Nascido , Recém-Nascido Prematuro , Pessoa de Meia-Idade , Software
3.
Med Image Anal ; 33: 127-133, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-27344104

RESUMO

The deformable atlas paradigm has been at the core of computational anatomy during the last two decades. Spatial normalization is the variant endowing the atlas with a coordinate system used for voxel-based aggregation of images across subjects and studies. This framework has largely contributed to the success of brain mapping. Brain spatial normalization, however, is still ill-posed because of the complexity of the human brain architecture and the lack of architectural landmarks in standard morphological MRI. Multi-atlas strategies have been developed during the last decade to overcome some difficulties in the context of segmentation. A new generation of registration algorithms embedding architectural features inferred for instance from diffusion or functional MRI is on the verge to improve the architectural value of spatial normalization. A better understanding of the architectural meaning of the cortical folding pattern will lead to use some sulci as complementary constraints. Improving the architectural compliance of spatial normalization may impose to relax the diffeomorphic constraint usually underlying atlas warping. A two-level strategy could be designed: in each region, a dictionary of templates of incompatible folding patterns would be collected and matched in a way or another using rare architectural information, while individual subjects would be aligned using diffeomorphisms to the closest template. Manifold learning could help to aggregate subjects according to their morphology. Connectivity-based strategies could emerge as an alternative to deformation-based alignment leading to match the connectomes of the subjects rather than images.


Assuntos
Algoritmos , Encéfalo/diagnóstico por imagem , Processamento de Imagem Assistida por Computador/métodos , Encéfalo/citologia , Mapeamento Encefálico , Conectoma , Humanos , Imageamento por Ressonância Magnética
4.
Neuroscience ; 311: 539-51, 2015 Dec 17.
Artigo em Inglês | MEDLINE | ID: mdl-26546471

RESUMO

Parkinson's disease (PD) is a well-characterized neurological disorder with regard to its neuropathological and symptomatic appearance. At the genetic level, mutations of particular genes, e.g. Parkin and DJ-1, were found in human hereditary PD with early onset. Neurotransmitter receptors constitute decisive elements in neural signal transduction. Furthermore, since they are often altered in neurological and psychiatric diseases, receptors have been successful targets for pharmacological agents. However, the consequences of PD-associated gene mutations on the expression of transmitter receptors are largely unknown. Therefore, we studied the expression of 16 different receptor binding sites of the neurotransmitters glutamate, GABA, acetylcholine, adrenaline, serotonin, dopamine and adenosine by means of quantitative receptor autoradiography in Parkin and DJ-1 knockout mice. These knockout mice exhibit electrophysiological and behavioral deficits, but do not show the typical dopaminergic cell loss. We demonstrated differential changes of binding site densities in eleven brain regions. Most prominently, we found an up-regulation of GABA(B) and kainate receptor densities in numerous cortical areas of Parkin and DJ-1 knockout mice, as well as increased NMDA but decreased AMPA receptor densities in different brain regions of the Parkin knockout mice. The alterations of three different glutamate receptor types may indicate the potential relevance of the glutamatergic system in the pathogenesis of PD. Furthermore, the cholinergic M1, M2 and nicotinic receptors as well as the adrenergic α2 and the adenosine A(2A) receptors showed differentially increased densities in Parkin and DJ-1 knockout mice. Taken together, knockout of the PD-associated genes Parkin or DJ-1 results in differential changes of neurotransmitter receptor densities, highlighting a possible role of altered non-dopaminergic, and in particular of glutamatergic neurotransmission in PD pathogenesis.


Assuntos
Encéfalo/metabolismo , Proteínas Oncogênicas/genética , Peroxirredoxinas/genética , Receptores de Neurotransmissores/metabolismo , Ubiquitina-Proteína Ligases/genética , Animais , Autorradiografia , Encéfalo/patologia , Masculino , Camundongos Endogâmicos C57BL , Camundongos Knockout , Proteínas Oncogênicas/deficiência , Transtornos Parkinsonianos/metabolismo , Transtornos Parkinsonianos/patologia , Peroxirredoxinas/deficiência , Proteína Desglicase DJ-1 , Ubiquitina-Proteína Ligases/deficiência
5.
J R Soc Interface ; 12(111): 20150734, 2015 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-26446561

RESUMO

The neuroimaging technique three-dimensional polarized light imaging (3D-PLI) provides a high-resolution reconstruction of nerve fibres in human post-mortem brains. The orientations of the fibres are derived from birefringence measurements of histological brain sections assuming that the nerve fibres­consisting of an axon and a surrounding myelin sheath­are uniaxial birefringent and that the measured optic axis is oriented in the direction of the nerve fibres (macroscopic model). Although experimental studies support this assumption, the molecular structure of the myelin sheath suggests that the birefringence of a nerve fibre can be described more precisely by multiple optic axes oriented radially around the fibre axis (microscopic model). In this paper, we compare the use of the macroscopic and the microscopic model for simulating 3D-PLI by means of the Jones matrix formalism. The simulations show that the macroscopic model ensures a reliable estimation of the fibre orientations as long as the polarimeter does not resolve structures smaller than the diameter of single fibres. In the case of fibre bundles, polarimeters with even higher resolutions can be used without losing reliability. When taking the myelin density into account, the derived fibre orientations are considerably improved.


Assuntos
Axônios/fisiologia , Encéfalo/fisiologia , Imageamento Tridimensional/métodos , Bainha de Mielina/fisiologia , Fibras Nervosas/fisiologia , Neuroimagem/métodos , Algoritmos , Birrefringência , Simulação por Computador , Humanos , Processamento de Imagem Assistida por Computador , Luz , Modelos Teóricos , Óptica e Fotônica
6.
Rofo ; 187(10): 892-8, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26415113

RESUMO

PURPOSE: To investigate the distribution of co-activation patterns of the recently identified ventral visual areas FG1 and FG2 of the posterior fusiform gyrus using the novel meta-analytic approach PaMiNI (Pattern Mining in NeuroImaging). MATERIALS AND METHODS: All neuroimaging experiments reporting activation foci within FG1 or FG2 were retrieved from the BrainMap database. The stereotaxic activation foci in standard reference space were analyzed with PaMiNI. Here, Gaussian mixture modeling was applied to the stereotaxic coordinates of all foci to identify the underlying brain regions of each dataset. Then, association analysis was performed to reveal frequent co-activations across the modeled brain regions. RESULTS: Co-activation patterns of FG1 were mainly found within the visual system, i.e. in early visual areas, and were symmetrically distributed across both hemispheres. FG2 features several extra-visual co-activations, mainly to inferior frontal, premotor and parietal regions. Furthermore, the co-activations of FG2 showed clear lateralization to the left FG2. CONCLUSION: FG1 shows characteristics of an intermediate visual area between the early ventral visual cortex and the category-specific higher-order areas. Co-activation patterns of FG2 indicate that FG2 is a higher-order visual area that probably corresponds to the posterior fusiform face area and partly the visual word-form area. Key points. Co-activation patterns of areas FG1 and FG2 were analyzed with PaMiNI. FG1 features mainly symmetric co-activations to areas of the visual system. FG2 shows several extra-visual co-activations, which are left-lateralized. FG1 corresponds to a hierarchically intermediate, FG2 to a higher-order visual area. The PaMiNI approach is extended to seed-specific mapping of co-activation patterns.


Assuntos
Lobo Temporal/fisiopatologia , Visão Ocular/fisiologia , Vias Visuais/fisiologia , Mapeamento Encefálico/métodos , Mineração de Dados/métodos , Dominância Cerebral/fisiologia , Humanos , Rede Nervosa/fisiologia , Reconhecimento Automatizado de Padrão
7.
Neuroimage ; 123: 200-11, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26254112

RESUMO

Historically, the human frontal pole (FP) has been considered as a single architectonic area. Brodmann's area 10 is located in the frontal lobe with known contributions in the execution of various higher order cognitive processes. However, recent cytoarchitectural studies of the FP in humans have shown that this portion of cortex contains two distinct cytoarchitectonic regions. Since architectonic differences are accompanied by differential connectivity and functions, the frontal pole qualifies as a candidate region for exploratory parcellation into functionally discrete sub-regions. We investigated whether this functional heterogeneity is reflected in distinct segregations within cytoarchitectonically defined FP-areas using meta-analytic co-activation based parcellation (CBP). The CBP method examined the co-activation patterns of all voxels within the FP as reported in functional neuroimaging studies archived in the BrainMap database. Voxels within the FP were subsequently clustered into sub-regions based on the similarity of their respective meta-analytically derived co-activation maps. Performing this CBP analysis on the FP via k-means clustering produced a distinct 3-cluster parcellation for each hemisphere corresponding to previously identified cytoarchitectural differences. Post-hoc functional characterization of clusters via BrainMap metadata revealed that lateral regions of the FP mapped to memory and emotion domains, while the dorso- and ventromedial clusters were associated broadly with emotion and social cognition processes. Furthermore, the dorsomedial regions contain an emphasis on theory of mind and affective related paradigms whereas ventromedial regions couple with reward tasks. Results from this study support previous segregations of the FP and provide meta-analytic contributions to the ongoing discussion of elucidating functional architecture within human FP.


Assuntos
Lobo Frontal/anatomia & histologia , Lobo Frontal/fisiologia , Algoritmos , Encéfalo/anatomia & histologia , Encéfalo/fisiologia , Mapeamento Encefálico/métodos , Análise por Conglomerados , Cognição/fisiologia , Emoções/fisiologia , Humanos , Imageamento por Ressonância Magnética/métodos , Vias Neurais/anatomia & histologia , Vias Neurais/fisiologia , Tomografia por Emissão de Pósitrons/métodos
8.
Neuroscience ; 285: 11-23, 2015 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-25451278

RESUMO

Parkinson's disease (PD) is the second most common neurodegenerative disorder, characterized by alterations of nigrostriatal dopaminergic neurotransmission. Compared to the wealth of data on the impairment of the dopamine system, relatively limited evidence is available concerning the role of major non-dopaminergic neurotransmitter systems in PD. Therefore, we comprehensively investigated the density and distribution of neurotransmitter receptors for glutamate, GABA, acetylcholine, adrenaline, serotonin, dopamine and adenosine in brains of homozygous aphakia mice being characterized by mutations affecting the Pitx3 gene. This genetic model exhibits crucial hallmarks of PD on the neuropathological, symptomatic and pharmacological level. Quantitative receptor autoradiography was used to characterize 19 different receptor binding sites in eleven brain regions in order to understand receptor changes on a systemic level. We demonstrated striking differential changes of neurotransmitter receptor densities for numerous receptor types and brain regions, respectively. Most prominent, a strong up-regulation of GABA receptors and associated benzodiazepine binding sites in different brain regions and concomitant down-regulations of striatal nicotinic acetylcholine and serotonergic receptor densities were found. Furthermore, the densities of glutamatergic kainate, muscarinic acetylcholine, adrenergic α1 and dopaminergic D2/D3 receptors were differentially altered. These results present novel insights into the expression of neurotransmitter receptors in Pitx3(ak) mice supporting findings on PD pathology in patients and indicating on the possible underlying mechanisms. The data suggest Pitx3(ak) mice as an appropriate new model to investigate the role of neurotransmitter receptors in PD. Our study highlights the relevance of non-dopaminergic systems in PD and for the understanding of its molecular pathology.


Assuntos
Encéfalo/metabolismo , Proteínas de Homeodomínio/metabolismo , Transtornos Parkinsonianos/metabolismo , Receptores de Neurotransmissores/metabolismo , Fatores de Transcrição/metabolismo , Acetilcolina/metabolismo , Adenosina/metabolismo , Animais , Dopamina/metabolismo , Epinefrina/metabolismo , Proteínas de Homeodomínio/genética , Homozigoto , Masculino , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Serotonina/metabolismo , Fatores de Transcrição/genética , Ácido gama-Aminobutírico/metabolismo
9.
Neuroimage ; 99: 525-32, 2014 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-24936682

RESUMO

The last two decades have seen an unprecedented development of human brain mapping approaches at various spatial and temporal scales. Together, these have provided a large fundus of information on many different aspects of the human brain including micro- and macrostructural segregation, regional specialization of function, connectivity, and temporal dynamics. Atlases are central in order to integrate such diverse information in a topographically meaningful way. It is noteworthy, that the brain mapping field has been developed along several major lines such as structure vs. function, postmortem vs. in vivo, individual features of the brain vs. population-based aspects, or slow vs. fast dynamics. In order to understand human brain organization, however, it seems inevitable that these different lines are integrated and combined into a multimodal human brain model. To this aim, we held a workshop to determine the constraints of a multi-modal human brain model that are needed to enable (i) an integration of different spatial and temporal scales and data modalities into a common reference system, and (ii) efficient data exchange and analysis. As detailed in this report, to arrive at fully interoperable atlases of the human brain will still require much work at the frontiers of data acquisition, analysis, and representation. Among them, the latter may provide the most challenging task, in particular when it comes to representing features of vastly different scales of space, time and abstraction. The potential benefits of such endeavor, however, clearly outweigh the problems, as only such kind of multi-modal human brain atlas may provide a starting point from which the complex relationships between structure, function, and connectivity may be explored.


Assuntos
Atlas como Assunto , Encéfalo/anatomia & histologia , Mapeamento Encefálico , Humanos
10.
Neuroimage ; 93 Pt 2: 260-75, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23702412

RESUMO

The frontal pole has more expanded than any other part in the human brain as compared to our ancestors. It plays an important role for specifically human behavior and cognitive abilities, e.g. action selection (Kovach et al., 2012). Evidence about divergent functions of its medial and lateral part has been provided, both in the healthy brain and in psychiatric disorders. The anatomical correlates of such functional segregation, however, are still unknown due to a lack of stereotaxic, microstructural maps obtained in a representative sample of brains. Here we show that the human frontopolar cortex consists of two cytoarchitectonically and functionally distinct areas: lateral frontopolar area 1 (Fp1) and medial frontopolar area 2 (Fp2). Based on observer-independent mapping in serial, cell-body stained sections of 10 brains, three-dimensional, probabilistic maps of areas Fp1 and Fp2 were created. They show, for each position of the reference space, the probability with which each area was found in a particular voxel. Applying these maps as seed regions for a meta-analysis revealed that Fp1 and Fp2 differentially contribute to functional networks: Fp1 was involved in cognition, working memory and perception, whereas Fp2 was part of brain networks underlying affective processing and social cognition. The present study thus disclosed cortical correlates of a functional segregation of the human frontopolar cortex. The probabilistic maps provide a sound anatomical basis for interpreting neuroimaging data in the living human brain, and open new perspectives for analyzing structure-function relationships in the prefrontal cortex. The new data will also serve as a starting point for further comparative studies between human and non-human primate brains. This allows finding similarities and differences in the organizational principles of the frontal lobe during evolution as neurobiological basis for our behavior and cognitive abilities.


Assuntos
Lobo Frontal/anatomia & histologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Mapeamento Encefálico , Cognição/fisiologia , Feminino , Lobo Frontal/fisiologia , Humanos , Imageamento por Ressonância Magnética , Masculino , Memória de Curto Prazo/fisiologia , Pessoa de Meia-Idade
11.
Front Psychol ; 4: 636, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24069009

RESUMO

To what extent does musical practice change the structure of the brain? In order to understand how long-lasting musical training changes brain structure, 20 male right-handed, middle-aged professional musicians and 19 matched controls were investigated. Among the musicians, 13 were pianists or organists with intensive practice regimes. The others were either music teachers at schools or string instrumentalists, who had studied the piano at least as a subsidiary subject, and practiced less intensively. The study was based on T1-weighted MR images, which were analyzed using deformation-based morphometry. Cytoarchitectonic probabilistic maps of cortical areas and subcortical nuclei as well as myeloarchitectonic maps of fiber tracts were used as regions of interest to compare volume differences in the brains of musicians and controls. In addition, maps of voxel-wise volume differences were computed and analyzed. Musicians showed a significantly better symmetric motor performance as well as a greater capability of controlling hand independence than controls. Structural MRI-data revealed significant volumetric differences between the brains of keyboard players, who practiced intensively and controls in right sensorimotor areas and the corticospinal tract as well as in the entorhinal cortex and the left superior parietal lobule. Moreover, they showed also larger volumes in a comparable set of regions than the less intensively practicing musicians. The structural changes in the sensory and motor systems correspond well to the behavioral results, and can be interpreted in terms of plasticity as a result of intensive motor training. Areas of the superior parietal lobule and the entorhinal cortex might be enlarged in musicians due to their special skills in sight-playing and memorizing of scores. In conclusion, intensive and specific musical training seems to have an impact on brain structure, not only during the sensitive period of childhood but throughout life.

12.
Curr Alzheimer Res ; 10(10): 1098-106, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22746244

RESUMO

Mild cognitive impairment (MCI) could be an auspicious candidate for an early marker of a beginning dementia. However, although MCI is accepted as a heterogeneous condition by now, performance testing or diagnosis is often based on a limited number of cognitive tests. Furthermore, there is still disagreement about the necessity to include subjective cognitive complaints as a diagnostic criterion. The current study intends to examine the character of MCI when diagnosis is based upon multiple cognitive domains and does not require the presence of subjective complaints. 130 subjects from the HelMA (Helmholtz Alliance for Mental Health in an Ageing Society) longitudinal study completed a comprehensive neuropsychological test-battery and were diagnosed as either normally-ageing controls or patients with MCI. The prevalence rate of MCI was as high as 46.2%, hereby exceeding most estimates of other studies. Patients with MCI performed worse than controls in each of the 29 administered tests with memory being the predominant impaired cognitive domain. Surprisingly, there was no single patient with a purely non-amnestic impairment, considerably contradicting hitherto existing studies. The rather different distribution of impairment and prevalence rate emphasizes the demand of testbatteries including all cognitive domains so that inferences about MCI are as all-encompassing as possible.


Assuntos
Disfunção Cognitiva/diagnóstico , Disfunção Cognitiva/epidemiologia , Disfunção Cognitiva/psicologia , Testes Neuropsicológicos , Idoso , Idoso de 80 Anos ou mais , Disfunção Cognitiva/complicações , Progressão da Doença , Feminino , Humanos , Estudos Longitudinais , Masculino , Transtornos da Memória/diagnóstico , Transtornos da Memória/etiologia , Pessoa de Meia-Idade , Prevalência , Análise de Regressão , Inquéritos e Questionários
13.
Brain Behav Evol ; 77(2): 67-78, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21335939

RESUMO

The prefrontal cortex is commonly associated with cognitive capacities related to human uniqueness: purposeful actions towards higher-level goals, complex social information processing, introspection, and language. Comparative investigations of the prefrontal cortex may thus shed more light on the neural underpinnings of what makes us human. Using histological data from 19 anthropoid primate species (6 apes including humans and 13 monkeys), we investigate cross-species relative size changes along the anterior (prefrontal) and posterior (motor) axes of the cytoarchitectonically defined frontal lobe in both hemispheres. Results reveal different scaling coefficients in the left versus right prefrontal hemisphere, suggest that the primary factor underlying the evolution of primate brain architecture is left hemispheric prefrontal hyperscaling, and indicate that humans are the extreme of a left prefrontal ape specialization in relative white to grey matter volume. These results demonstrate a neural adaptive shift distinguishing the ape from the monkey radiation possibly related to a cognitive grade shift between (great) apes and other primates.


Assuntos
Evolução Biológica , Lateralidade Funcional/fisiologia , Hominidae/anatomia & histologia , Córtex Pré-Frontal/anatomia & histologia , Animais , Hominidae/crescimento & desenvolvimento , Humanos , Masculino , Córtex Pré-Frontal/crescimento & desenvolvimento
14.
Neuroimage ; 43(2): 269-87, 2008 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-18706506

RESUMO

The progression of neurodegenerative diseases as well as healthy aging is accompanied by structural changes of the brain. These changes are often only subtle when considered over time intervals of several months. Therefore morphometrical techniques for their detection in longitudinally acquired MR images must be highly sensitive, and they require a careful validation. In the present study, a novel processing chain for a longitudinal analysis based on deformation field morphometry is described. Procedures for its quantitative validation are also reported: Deformation fields were computed for the simulation of non-linear, local structural changes of human brains. Applying these deformation fields to "original" MR images yielded deformed MR images. The volume changes defined by the deformation fields represented the standard, against which the results of the longitudinal analysis of each pair of original and deformed MR image were compared. The proposed processing chain enabled to localize and to quantify simulated local atrophies near the cortex as well as in deep brain structures. An exemplary analysis of serial MR images of a patient suffering from an atypical Parkinson syndrome (cortico-basal degeneration, CBD) and healthy control subjects is presented, showing a characteristic pattern of volume changes in the brain of the patient which is strikingly different from the controls' patterns of changes.


Assuntos
Algoritmos , Encéfalo/patologia , Interpretação de Imagem Assistida por Computador/métodos , Imageamento por Ressonância Magnética/métodos , Doenças Neurodegenerativas/patologia , Reconhecimento Automatizado de Padrão/métodos , Técnica de Subtração , Feminino , Humanos , Aumento da Imagem/métodos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Processamento de Sinais Assistido por Computador
15.
Neuroimage ; 42(3): 1127-41, 2008 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-18585468

RESUMO

The basal forebrain contains several interdigitating anatomical structures, including the diagonal band of Broca, the basal nucleus of Meynert, the ventral striatum, and also cell groups underneath the globus pallidus that bridge the centromedial amygdala to the bed nucleus of the stria terminalis. Among the cell populations, the magnocellular, cholinergic corticopetal projection neurons have received particular attention due to their loss in Alzheimer's disease. In MRI images, the precise delineation of these structures is difficult due to limited spatial resolution and contrast. Here, using microscopic delineations in ten human postmortem brains, we present stereotaxic probabilistic maps of the basal forebrain areas containing the magnocellular cell groups. Cytoarchitectonic mapping was performed in silver stained histological serial sections. The positions and the extent of the magnocellular cell groups within the septum (Ch1-2), the horizontal limb of the diagonal band (Ch3), and in the sublenticular part of the basal forebrain (Ch4) were traced in high-resolution digitized histological sections, 3D reconstructed, and warped to the reference space of the MNI single subject brain. The superposition of the cytoarchitectonic maps in the MNI brain shows the intersubject variability of the various Ch compartments and their stereotaxic position relative to other brain structures. Both the right and left Ch4 regions showed significantly smaller volumes when age was considered as a covariate. Probabilistic maps of compartments of the basal forebrain magnocellular system are now available as an open source reference for correlation with fMRI, PET, and structural MRI data of the living human brain.


Assuntos
Imageamento Tridimensional , Neurônios/citologia , Prosencéfalo/citologia , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
16.
Neuroimage ; 37(4): 1061-5; discussion 1066-8, 2007 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-17870622

RESUMO

The present paper reviews that macroanatomical landmarks are problematic for a reliable and sufficiently precise localization of clusters of activation obtained by functional imaging because sulcal and gyral patterns are extremely variable and macroanatomical landmarks do not match (in nearly all cases) architectonically defined borders. It argues that cytoarchitectonic probabilistic maps currently offer the most precise tool for the localization of brain functions as obtained from functional imaging studies. Finally, it provides some examples that cytoarchitecture is more than localization with respect to a particular brain region because it reflects the inner organization of cortical areas and, furthermore, functional principles of the brain.


Assuntos
Córtex Cerebral/anatomia & histologia , Animais , Córtex Auditivo/anatomia & histologia , Córtex Auditivo/fisiologia , Mapeamento Encefálico , Córtex Cerebral/citologia , Análise por Conglomerados , Humanos , Processamento de Imagem Assistida por Computador/estatística & dados numéricos , Macaca , Modelos Estatísticos , Córtex Motor/anatomia & histologia , Córtex Motor/fisiologia , Córtex Visual/anatomia & histologia , Córtex Visual/fisiologia
17.
Neuroscience ; 136(3): 715-28, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-16344146

RESUMO

In this study we explored whether a postnatal doubling of the total number of neurons occurs in the human Brodmann areas 44 and 45 (Broca's area). We describe the most recent error prediction formulae and their application for the modern stereological estimators for volume and number of neurons. We estimated the number of neurons in 3D optical disector probes systematically random sampled throughout the entire Brodmann areas (BA) 44 and 45 in developing and young adult cases. In the relatively small number of male and female cases studied no substantial postnatal increase in total number of neurons occurred in areas 44 and 45; the volume of these areas reached adult values around 7 years. In addition, we did find indications that a shift from a right-over-left to a left-over-right asymmetry may occur in the volume of BA 45 during postnatal development. No major asymmetry in total number of neurons in BA 44 and 45 was detected.


Assuntos
Lobo Frontal/citologia , Neurônios/fisiologia , Técnicas Estereotáxicas , Adulto , Fatores Etários , Contagem de Células/métodos , Criança , Feminino , Lobo Frontal/crescimento & desenvolvimento , Lateralidade Funcional , Humanos , Lactente , Recém-Nascido , Masculino , Mudanças Depois da Morte , Fatores Sexuais
18.
Anat Embryol (Berl) ; 210(5-6): 373-86, 2005 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-16249867

RESUMO

Recent progress in anatomical and functional MRI has revived the demand for a reliable, topographic map of the human cerebral cortex. Till date, interpretations of specific activations found in functional imaging studies and their topographical analysis in a spatial reference system are, often, still based on classical architectonic maps. The most commonly used reference atlas is that of Brodmann and his successors, despite its severe inherent drawbacks. One obvious weakness in traditional, architectural mapping is the subjective nature of localising borders between cortical areas, by means of a purely visual, microscopical examination of histological specimens. To overcome this limitation, more objective, quantitative mapping procedures have been established in the past years. The quantification of the neocortical, laminar pattern by defining intensity line profiles across the cortical layers, has a long tradition. During the last years, this method has been extended to enable a reliable, reproducible mapping of the cortex based on image analysis and multivariate statistics. Methodological approaches to such algorithm-based, cortical mapping were published for various architectural modalities. In our contribution, principles of algorithm-based mapping are described for cyto- and receptorarchitecture. In a cytoarchitectural parcellation of the human auditory cortex, using a sliding window procedure, the classical areal pattern of the human superior temporal gyrus was modified by a replacing of Brodmann's areas 41, 42, 22 and parts of area 21, with a novel, more detailed map. An extension and optimisation of the sliding window procedure to the specific requirements of receptorarchitectonic mapping, is also described using the macaque central sulcus and adjacent superior parietal lobule as a second, biologically independent example. Algorithm-based mapping procedures, however, are not limited to these two architectural modalities, but can be applied to all images in which a laminar cortical pattern can be detected and quantified, e.g. myeloarchitectonic and in vivo high resolution MR imaging. Defining cortical borders, based on changes in cortical lamination in high resolution, in vivo structural MR images will result in a rapid increase of our knowledge on the structural parcellation of the human cerebral cortex.


Assuntos
Mapeamento Encefálico/métodos , Córtex Cerebelar/anatomia & histologia , Algoritmos , Animais , Córtex Auditivo/anatomia & histologia , Córtex Auditivo/química , Córtex Auditivo/citologia , Autorradiografia , Química Encefálica , Córtex Cerebelar/química , Córtex Cerebelar/citologia , Análise por Conglomerados , Humanos , Processamento de Imagem Assistida por Computador , Macaca , Imageamento por Ressonância Magnética , Análise Multivariada , Receptores de Neurotransmissores/análise , Telencéfalo/anatomia & histologia , Telencéfalo/química , Telencéfalo/citologia
19.
Anat Embryol (Berl) ; 210(5-6): 343-52, 2005 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-16208455

RESUMO

Probabilistic maps of neocortical areas and subcortical fiber tracts, warped to a common reference brain, have been published using microscopic architectonic parcellations in ten human postmortem brains. The maps have been successfully applied as topographical references for the anatomical localization of activations observed in functional imaging studies. Here, for the first time, we present stereotaxic, probabilistic maps of the hippocampus, the amygdala and the entorhinal cortex and some of their subdivisions. Cytoarchitectonic mapping was performed in serial, cell-body stained histological sections. The positions and the extent of cytoarchitectonically defined structures were traced in digitized histological sections, 3-D reconstructed and warped to the reference space of the MNI single subject brain using both linear and non-linear elastic tools of alignment. The probability maps and volumes of all structures were calculated. The precise localization of the borders of the mapped regions cannot be predicted consistently by macroanatomical landmarks. Many borders, e.g. between the subiculum and entorhinal cortex, subiculum and Cornu ammonis, and amygdala and hippocampus, do not match sulcal landmarks such as the bottom of a sulcus. Only microscopic observation enables the precise localization of the borders of these brain regions. The superposition of the cytoarchitectonic maps in the common spatial reference system shows a considerably lower degree of intersubject variability in size and position of the allocortical structures and nuclei than the previously delineated neocortical areas. For the first time, the present observations provide cytoarchitectonically verified maps of the human amygdala, hippocampus and entorhinal cortex, which take into account the stereotaxic position of the brain structures as well as intersubject variability. We believe that these maps are efficient tools for the precise microstructural localization of fMRI, PET and anatomical MR data, both in healthy and pathologically altered brains.


Assuntos
Tonsila do Cerebelo/anatomia & histologia , Mapeamento Encefálico/métodos , Córtex Entorrinal/anatomia & histologia , Hipocampo/anatomia & histologia , Idoso , Idoso de 80 Anos ou mais , Tonsila do Cerebelo/citologia , Cadáver , Interpretação Estatística de Dados , Córtex Entorrinal/citologia , Feminino , Hipocampo/citologia , Humanos , Imageamento Tridimensional , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Tomografia por Emissão de Pósitrons , Software , Técnicas Estereotáxicas
20.
Anat Embryol (Berl) ; 210(5-6): 401-6, 2005 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-16170539

RESUMO

Although it is generally accepted that human superior temporal gyrus is activated by a huge variety of auditory and linguistic tasks, little is known about the exact positions and extents of cortical areas that are located on the lateral convexity of the gyrus (e.g., Brodmann's area 22). Such information, however, is relevant for a rigorous testing of structural-functional relationships in both normal volunteers and patients suffering from disorders of auditory and language perception. The present combined cytoarchitectonic and receptorarchitectonic study identifies a distinct area (Te3) in the lateral bulge of the superior temporal gyrus by using an algorithm-based approach for the detection of cortical borders. Our mapping data show that, in contrast to Brodmann's area (BA) 22, only small portions of Te3 reach the dorsal and ventral banks of the gyrus. Therefore, we labelled the newly defined area as "Te3" and not as "BA 22". The cytoarchitectonically defined borders of Te3 coincide with abrupt changes in the receptorarchitecture of several classical neurotransmitters, suggesting that Te3 represents a functionally relevant area of the human superior temporal gyrus. Since position and extent of area Te3 varied considerably between subjects, probability maps were created that show for each voxel of the standard references space, the frequency with which Te3 was present in it. These maps, in combination with previously published maps of the primary auditory cortex, can directly be compared with functional imaging data, and may open new perspectives for the analysis of structural-functional correlations in the human auditory and language systems.


Assuntos
Córtex Auditivo/anatomia & histologia , Mapeamento Encefálico/métodos , Lobo Temporal/anatomia & histologia , Algoritmos , Córtex Auditivo/química , Córtex Auditivo/citologia , Córtex Auditivo/fisiologia , Química Encefálica , Cadáver , Humanos , Imageamento Tridimensional , Idioma , Receptores de Neurotransmissores/análise , Lobo Temporal/química , Lobo Temporal/citologia , Lobo Temporal/fisiologia
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