K Zilles

RWTH Aachen University, Aachen, North Rhine-Westphalia, Germany

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Publications (392)1374.54 Total impact

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    ABSTRACT: 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. Copyright © 2014. Published by Elsevier Ltd.
    Neuroscience 11/2014; · 3.12 Impact Factor
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    ABSTRACT: The language network is a well-defined large-scale neural network of anatomically and functionally interacting cortical areas. The successful language process requires the transmission of information between these areas. Since neurotransmitter receptors are key molecules of information processing, we hypothesized that cortical areas which are part of the same functional language network may show highly similar multireceptor expression pattern (“receptor fingerprint”), whereas those that are not part of this network should have different fingerprints. Here we demonstrate that the relation between the densities of 15 different excitatory, inhibitory and modulatory receptors in eight language related areas are highly similar and differ considerably from those of 18 other brain regions not directly involved in language processing. Thus, the fingerprints of all cortical areas underlying a large-scale cognitive domain such as language is a characteristic, functionally relevant feature of this network and an important prerequisite for the underlying neuronal processes of language functions.
    Cortex 08/2014; · 6.16 Impact Factor
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    ABSTRACT: 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 the 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.
    NeuroImage 06/2014; · 6.25 Impact Factor
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    ABSTRACT: Cholinergic neurons of the medial forebrain are considered important contributors to brain plasticity and neuromodulation. A reduction of cholinergic innervation can lead to pathophysiological changes of neurotransmission and is observed in Alzheimer's disease. Here we report on six patients with mild to moderate Alzheimer's disease (AD) treated with bilateral low-frequency deep brain stimulation (DBS) of the nucleus basalis of Meynert (NBM). During a four-week double-blind sham-controlled phase and a subsequent 11-month follow-up open label period, clinical outcome was assessed by neuropsychological examination using the Alzheimer's Disease Assessment Scale-cognitive subscale as the primary outcome measure. Electroencephalography and [(18)F]-fluoro-desoxyglucose positron emission tomography were, besides others, secondary endpoints. On the basis of stable or improved primary outcome parameters twelve months after surgery, four of the six patients were considered responders. No severe or non-transitional side effects related to the stimulation were observed. Taking into account all limitations of a pilot study, we conclude that DBS of the NBM is both technically feasible and well tolerated.Molecular Psychiatry advance online publication, 6 May 2014; doi:10.1038/mp.2014.32.
    Molecular Psychiatry 05/2014; · 15.15 Impact Factor
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    ABSTRACT: Healthy aging is accompanied by a decrease in cognitive and motor capacities. In a network associated with movement initiation, we investigated age-related changes of functional connectivity (FC) as well as regional atrophy in a sample of 232 healthy subjects (age range 18-85 years). To this end, voxel-based morphometry and whole-brain resting-state FC were analyzed for the supplementary motor area (SMA), anterior midcingulate cortex (aMCC) and bilateral striatum (Str). To assess the specificity of age-related effects, bilateral primary sensorimotor cortex (S1/M1) closely associated with motor execution was used as control seeds. All regions showed strong reduction of gray matter volume with age. Corrected for this regional atrophy, the FC analysis revealed an age × seed interaction for each of the bilateral Str nodes against S1/M1 with consistent age-related decrease in FC with bilateral caudate nucleus and anterior putamen. Specific age-dependent FC decline of SMA was found in bilateral central insula and the adjacent frontal operculum. aMCC showed exclusive age-related decoupling from the anterior cingulate motor area. The present study demonstrates network as well as node-specific age-dependent FC decline of the SMA and aMCC to highly integrative cortical areas involved in cognitive motor control. FC decrease in addition to gray matter atrophy within the Str may provide a substrate for the declining motor control in elderly. Finally, age-related FC changes in both the network for movement initiation as well as the network for motor execution are not explained by regional atrophy in the healthy aging brain.
    Brain Structure and Function 01/2014; · 7.84 Impact Factor
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    ABSTRACT: 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.
    NeuroImage 05/2013; · 6.25 Impact Factor
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    ABSTRACT: 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.
    Frontiers in Psychology 01/2013; 4:636. · 2.80 Impact Factor
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    ABSTRACT: In a previous meta-analysis across almost 200 neuroimaging experiments, working memory for object location showed significantly stronger convergence on the posterior superior frontal gyrus, whereas working memory for identity showed stronger convergence on the posterior inferior frontal gyrus (dorsal to, but overlapping with Brodmann’s area BA 44). As similar locations have been discussed as part of a dorsal frontal—superior parietal reach system and an inferior frontal grasp system, the aim of the present study was to test whether the regions of working-memory related “what” and “where” processing show a similar distinction in parietal connectivity. The regions that were found in the previous meta-analysis were used as seeds for functional connectivity analyses using task-based meta-analytic connectivity modelling and task-independent resting state correlations. While the ventral seed showed significantly stronger connectivity with the bilateral intraparietal sulcus (IPS), the dorsal seed showed stronger connectivity with the bilateral posterior inferior parietal and the medial superior parietal lobule. The observed connections of regions involved in memory for object location and identity thus clearly demonstrate a distinction into separate pathways that resemble the parietal connectivity patterns of the dorsal and ventral premotor cortex in non-human primates and humans. It may hence be speculated that memory for a particular location and reaching towards it as well as object memory and finger positioning for manipulation may rely on shared neural systems. Moreover, the ensuing regions, in turn, featured differential connectivity with the bilateral ventral and dorsal extrastriate cortex, suggesting largely segregated bilateral connectivity pathways from the dorsal visual cortex via the superior and inferior parietal lobules to the dorsal posterior frontal cortex and from the ventral visual cortex via the IPS to the ventral posterior frontal cortex that may underlie action and cognition.
    Brain Structure and Function 11/2012; · 7.84 Impact Factor
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    ABSTRACT: Large-scale neuroimaging databases provide a rich fundus of functional neuroimaging experiments exhibiting maximum activation coordinates for specific task conditions. Aiming to explore major neuronal networks of the human brain, we developed a meta-analytic pattern-mining approach which combines Gaussian mixture modeling with the Apriori algorithm to identify frequent activation patterns within these databases. The approach has been implemented in the PaMiNI (Pattern Mining in NeuroImaging) system, providing manifold facilities for the finding, inspection, and analysis of relevant patterns. After briefly sketching the background of PaMiNI, we give an overview of the system and describe its architecture. Using an example application, a system walkthrough illustrates how PaMiNI can be used for the discovery of networks comprising functionally connected brain regions.
    Computer-Based Medical Systems (CBMS), 2012 25th International Symposium on; 01/2012
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    ABSTRACT: Present knowledge about the serotonergic system in birdbrains is very limited, although the pigeon was used as an animal model in various studies focused on the behavioral effects of serotonergic transmission. In the mammalian brain the 5-HT(1A) receptor is the most widespread serotonin receptor type, and is involved in various functions. Less is known about the distribution of 5-HT(1A) receptors in the avian species. Therefore, we analyzed serotonin 5-HT(1A) receptor binding sites in the pigeon brain using quantitative in vitro receptor autoradiography with the selective radioligand [³H]-8-hydroxy-2-(di-n-propylamino)tetralin ([³H]-8-OH-DPAT). The receptor is differentially distributed throughout the pigeon brain. High levels of 5-HT(1A) receptors are found in the nucleus pretectalis (PT). Moderate densities were detected in the tectum, as well as in the telencephalic nidopallium and hyperpallium. Very low levels were found in the hippocampal formation, the amygdaloid complex, the basal ganglia, and several thalamic nuclei. Furthermore, local variations in 5-HT(1A) receptor densities support the concept of further subdivisions of the entopallium. The regional distribution patterns of 5-HT(1A) receptors mostly display a similar distribution as found in homologue brain structures of mammals.
    Neuroscience 11/2011; 200:1-12. · 3.12 Impact Factor
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    ABSTRACT: 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.
    Brain Behavior and Evolution 02/2011; 77(2):67-78. · 2.89 Impact Factor
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    ABSTRACT: Genetic control over morphological variability of primary sulci and gyri is of great interest in the evolutionary, developmental and clinical neurosciences. Primary structures emerge early in development and their morphology is thought to be related to neuronal differentiation, development of functional connections and cortical lateralization. We measured the proportional contributions of genetics and environment to regional variability, testing two theories regarding regional modulation of genetic influences by ontogenic and phenotypic factors. Our measures were surface area, and average length and depth of eleven primary cortical sulci from high-resolution MR images in 180 pedigreed baboons. Average heritability values for sulcal area, depth and length (h(2)(Area)=.38+/-.22; h(2)(Depth)=.42+/-.23; h(2)(Length)=.34+/-.22) indicated that regional cortical anatomy is under genetic control. The regional pattern of genetic contributions was complex and, contrary to previously proposed theories, did not depend upon sulcal depth, or upon the sequence in which structures appear during development. Our results imply that heritability of sulcal phenotypes may be regionally modulated by arcuate U-fiber systems. However, further research is necessary to unravel the complexity of genetic contributions to cortical morphology.
    NeuroImage 11/2010; 53(3):1126-34. · 6.25 Impact Factor
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    ABSTRACT: Circling behaviour of the ci2 rat mutant has been associated with an abnormal laterality concerning nigrostriatal and vestibular dopamine content and densities of several neurotransmitter receptors. Since not only subcortical, but also cortical activity subserve behavioural asymmetry, we applied quantitative in vitro receptor autoradiography to determine the densities of twenty neurotransmitter receptors in three areas of the motor cortex (Fr1, Fr2, Fr3) of the left and right hemispheres in adult male circling mutant rats (ci2/ci2), non-circling littermates (ci2/+) and aged-matched rats from the background strain (LEW/Ztm, wild type). Rats had previously been monitored for motor behaviour and swimming abilities. Wild type and ci2/+ rats did not differ from the behavioural point of view, whereas ci2/ci2 animals were characterized by pronounced lateralized circling behaviour and were not able to perform the swimming test correctly. Left Fr2 of wild type rats contained significantly lower NMDA receptor densities than its right counterpart. No interhemispheric differences were found in the motor cortex of ci2/+ or ci2/ci2 animals. All three areas of wild type rats contain higher GABA(A) and adenosine A(1) receptor densities than those of ci2/+ and ci2/ci2 animals, respectively. Serotonin 5-HT(2) receptor densities were significantly lower in the motor cortex of ci2/ci2 animals than in that of their heterozygous littermates. Thus, since the ci2 rat mutant presents a wide range of behavioural and neurochemical lateralization anomalies, in addition to representing a model of Usher syndrome type 1, it may prove useful to understand the mechanisms underlying abnormal rotational behaviour and its relevance as a model of disturbances in cerebral asymmetry and their consequences.
    Neuroscience 10/2010; 170(2):542-50. · 3.12 Impact Factor
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    ABSTRACT: Faces convey a multitude of information in social interaction, among which are trustworthiness and attractiveness. Humans process and evaluate these two dimensions very quickly due to their great adaptive importance. Trustworthiness evaluation is crucial for modulating behavior toward strangers; attractiveness evaluation is a crucial factor for mate selection, possibly providing cues for reproductive success. As both dimensions rapidly guide social behavior, this study tests the hypothesis that both judgments may be subserved by overlapping brain networks. To this end, we conducted an activation likelihood estimation meta-analysis on 16 functional magnetic resonance imaging studies pertaining to facial judgments of trustworthiness and attractiveness. Throughout combined, individual, and conjunction analyses on those two facial judgments, we observed consistent maxima in the amygdala which corroborates our initial hypothesis. This finding supports the contemporary paradigm shift extending the amygdala's role from dominantly processing negative emotional stimuli to processing socially relevant ones. We speculate that the amygdala filters sensory information with evolutionarily conserved relevance. Our data suggest that such a role includes not only "fight-or-flight" decisions but also social behaviors with longer term pay-off schedules, e.g., trustworthiness and attractiveness evaluation.
    Brain Structure and Function 10/2010; 215(3-4):209-23. · 7.84 Impact Factor
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    ABSTRACT: Spreading depression (SD), a self-propagating depolarization of neurons and glia, is believed to play a role in different neurological disorders including migraine aura and acute brain ischaemia. Initiation and propagation of SD modulate excitability of neuronal network. A brief period of excitation heralds SD which is immediately followed first by prolonged nerve cell depression and later by an excitatory phase. The aim of the present study was to characterize local and remote transmitter receptor changes after propagation of cortical SD. Quantitative receptor autoradiography was used to asses 16 transmitter receptor types in combined striatum-hippocampus-cortex slices of the rat 1 h after induction of cortical SD. In neocortical tissues, local increases of glutamate NMDA, AMPA, and kainate receptor binding sites were observed. In addition to up-regulation of ionotropic glutamate receptors, receptor binding sites of GABA(A), muscarinic M1 and M2, adrenergic alpha(1) and alpha(2), and serotonergic 5-HT(2) receptors were increased in the hippocampus. Cortical SD also upregulated NMDA, AMPA, kainate, GABA(A), serotonergic 5-HT(2), adrenergic alpha(2) and dopaminergic D1 receptor binding sites in the striatum. These findings indicate selective changes in several receptors binding sites both in cortical and subcortical regions by SD which may explain delayed excitatory phase after SD. Mapping of receptor changes by cortical SD increases our understanding of the mechanism of SD action in associated neurological disorders.
    Neuroscience 09/2009; 163(4):1340-52. · 3.12 Impact Factor
  • NeuroImage 07/2009; 47. · 6.25 Impact Factor
  • NeuroImage 07/2009; 40(01). · 6.25 Impact Factor
  • NeuroImage 07/2009; 47. · 6.25 Impact Factor
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    ABSTRACT: Pentylenetetrazole (PTZ) is a convulsant used to model epileptic seizures in rats. In the PTZ-model, altered heat shock protein 27 (HSP-27) expression highlights seizure-affected astrocytes, which play an important role in glutamate and GABA metabolism. This raises the question whether impaired neurotransmitter metabolism leads to an imbalance in neurotransmitter receptor expression. Consequently, we investigated the effects of seizures on the densities of seven different neurotransmitter receptors in rats which were repeatedly treated with PTZ (40 mg/kg) over a period of 14 days. Quantitative in vitro receptor autoradiography was used to measure the regional binding site densities of the glutamate alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA), kainate and N-methyl-D-aspartate (NMDA) receptors, the adenosine receptor type 1 (A(1)), which is part of the system controlling glutamate release, and the gamma-aminobutyric acid (GABA) receptors GABA(A) and GABA(B) as well as the GABA(A)-associated benzodiazepine (BZ) binding sites in each rat. Our results demonstrate altered receptor densities in brain regions of PTZ-treated animals, including the HSP-27 expressing foci (i.e. amygdala, piriform and entorhinal cortex, dentate gyrus). A general decrease of kainate receptor densities was observed together with an increase of NMDA binding sites in the hippocampus, the somatosensory, piriform and the entorhinal cortices. Furthermore, A(1) binding sites were decreased in the amygdala and hippocampal CA1 region (CA1), while BZ binding sites were increased in the dentate gyrus and CA1. Our data demonstrate the impact of PTZ induced seizures on the densities of kainate, NMDA, A(1) and BZ binding sites in epileptic brain. These changes are not restricted to regions showing glial impairment. Thus, an altered balance between different excitatory (NMDA) and modulatory receptors (A(1), BZ binding sites, kainate) shows a much wider regional distribution than that of glial HSP-27 expression, indicating that receptor changes are not following the glial stress responses, but may precede the HSP-27 expression.
    Neuroscience 05/2009; 163(1):490-9. · 3.12 Impact Factor
  • NeuroImage 01/2009; 47. · 6.25 Impact Factor

Publication Stats

17k Citations
1,374.54 Total Impact Points

Institutions

  • 2014
    • RWTH Aachen University
      Aachen, North Rhine-Westphalia, Germany
  • 1999–2013
    • Forschungszentrum Jülich
      • Institute of Neurosciences and Medicine (INM)
      Düren, North Rhine-Westphalia, Germany
  • 2011
    • University College London
      • Institute of Archaeology
      Londinium, England, United Kingdom
  • 1989–2011
    • Heinrich-Heine-Universität Düsseldorf
      • • C. u. O. Vogt-Institut für Hirnforschung
      • • Institut für Lasermedizin
      • • Neurologische Klinik
      • • Brain Research Institute
      Düsseldorf, North Rhine-Westphalia, Germany
  • 2008
    • Rutgers, The State University of New Jersey
      • Center for Molecular and Behavioral Neuroscience
      New Brunswick, NJ, United States
  • 2007
    • Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center
      Torrance, California, United States
  • 2006
    • IME Metallurgy
      Aachen, North Rhine-Westphalia, Germany
  • 2005–2006
    • Koninklijke Nederlandse Akademie van Wetenschappen
      Amsterdamo, North Holland, Netherlands
    • University of Cambridge
      • Department of Psychiatry
      Cambridge, ENG, United Kingdom
  • 1980–2004
    • University of Bonn
      • Anatomisches Institut
      Bonn, North Rhine-Westphalia, Germany
  • 2003
    • Seoul National University
      • Department of Nuclear Medicine
      Seoul, Seoul, South Korea
  • 2002
    • Universitätsklinikum Düsseldorf
      Düsseldorf, North Rhine-Westphalia, Germany
  • 2000–2002
    • Tohoku University
      • Institute of Development, Aging and Cancer
      Sendai-shi, Miyagi-ken, Japan
    • University of Guelph
      • Department of Psychology
      Guelph, Ontario, Canada
    • Otto-von-Guericke-Universität Magdeburg
      • Institute of Psychology I (IPSY)
      Magdeburg, Saxony-Anhalt, Germany
    • Sociaal en Cultureel Planbureau
      's-Gravenhage, South Holland, Netherlands
    • Kyoto University
      • Primate Research Institute
      Kyoto, Kyoto-fu, Japan
  • 2001
    • Università degli studi di Parma
      • Dipartimento di Neuroscienze
      Parma, Emilia-Romagna, Italy
  • 2000–2001
    • University of Leipzig
      • Veterinär-Anatomisches Institut
      Leipzig, Saxony, Germany
  • 1994–2001
    • Karolinska Institutet
      • Institutionen för neurovetenskap
      Solna, Stockholm, Sweden
    • Beijing Medical University
      • Department of Cell Biology
      Peping, Beijing, China
  • 1995
    • Universidad de Las Palmas de Gran Canaria
      • Department of Morphology
      Las Palmas, Canary Islands, Spain
    • Armed Forces Institute of Pathology
      Ralalpindi, Punjab, Pakistan
  • 1993
    • University of Tuebingen
      Tübingen, Baden-Württemberg, Germany
    • Semmelweis University
      • Department of Anatomy, Histology and Embryology
      Budapeŝto, Budapest, Hungary
  • 1989–1992
    • University of Wuerzburg
      Würzburg, Bavaria, Germany
  • 1983–1991
    • University of Cologne
      • • Institute of Anatomy I
      • • Institute for Forensic Medicine
      Köln, North Rhine-Westphalia, Germany
  • 1978–1982
    • Christian-Albrechts-Universität zu Kiel
      • Anatomisches Institut
      Kiel, Schleswig-Holstein, Germany
  • 1976
    • Hochschule Hannover
      Hanover, Lower Saxony, Germany
    • University of Münster
      • Institute of Physiology
      Muenster, North Rhine-Westphalia, Germany
  • 1973
    • Hannover Medical School
      Hanover, Lower Saxony, Germany