Kuhn, Hans-Jürg

[["dc.bibliographiccitation.firstpage","1"],["dc.bibliographiccitation.issue","1"],["dc.bibliographiccitation.journal","Cell and Tissue Research"],["dc.bibliographiccitation.lastpage","13"],["dc.bibliographiccitation.volume","316"],["dc.contributor.author","Knabe, Wolfgang"],["dc.contributor.author","Washausen, Stefan"],["dc.contributor.author","Brunnett, G."],["dc.contributor.author","Kuhn, H. J."],["dc.date.accessioned","2018-11-07T10:49:47Z"],["dc.date.available","2018-11-07T10:49:47Z"],["dc.date.issued","2004"],["dc.description.abstract","Whether rhombomere-specific patterns of apoptosis exist in the developing hindbrain of vertebrates is under debate. We have investigated the sequence of apoptotic events in three-dimensionally reconstructed hindbrains of Tupaia belangeri (8- to 19-somite embryos). Apoptotic cells were identified by structural criteria and by applying an in situ tailing technique to visualize DNA fragmentation. Seven rhombomeres originated from three pro-rhombomeres. Among pre-migratory neural crest cells in the dorsal thirds of the neural folds, the earliest apoptotic concentrations appeared in the developing third rhombomere (r3). Dorsal apoptotic maxima then persisted in r3, extended from r3 to r2, and also arose in r5. Transverse apoptotic bands increased the total amount of apoptotic cells in odd-numbered rhombomeres first in r3 and, with a delay, also in r5. This sequence of apoptotic events was paralleled by an approximate rostrocaudal sequence of neural crest cell delamination from the even-numbered rhombomeres. Thus, large-scale apoptosis in r3 and r5 helped to establish crest-free zones that segregated streams of migrating neural crest cells adjacent to r2, r4, and r6. The sequence of apoptotic events observed in the dorsal thirds of rhombomeres matches that reported for the chick embryo. Other shared features are apoptotic peaks in the position of a circumscribed ventricular protrusion of fusing parts of the neural folds in r1 and r2, and Y-shaped apoptotic patterns composed of apoptotic maxima in the dorsal and lateral thirds of r1, r2, and r3. These rhombomere-specific patterns of apoptosis may therefore represent a conserved character, at least in amniotes."],["dc.identifier.doi","10.1007/s00441-004-0855-0"],["dc.identifier.isi","000220298800001"],["dc.identifier.pmid","14986099"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/48509"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Springer"],["dc.relation.issn","0302-766X"],["dc.title","Rhombomere-specific patterns of apoptosis in the tree shrew Tupaia belangeri"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","PII S0165-0270(02)00247-9"],["dc.bibliographiccitation.firstpage","169"],["dc.bibliographiccitation.issue","2"],["dc.bibliographiccitation.journal","Journal of Neuroscience Methods"],["dc.bibliographiccitation.lastpage","180"],["dc.bibliographiccitation.volume","121"],["dc.contributor.author","Knabe, Wolfgang"],["dc.contributor.author","Washausen, Stefan"],["dc.contributor.author","Brunnett, G."],["dc.contributor.author","Kuhn, H. R."],["dc.date.accessioned","2018-11-07T09:42:12Z"],["dc.date.available","2018-11-07T09:42:12Z"],["dc.date.issued","2002"],["dc.description.abstract","The present study demonstrates how, predominantly by external fiducials, histological serial sections used to reconstruct patterns of individually marked cellular events in large organs or whole embryos can be realigned with the help of 'reference series'. Resin-embedded embryos were cut at 1 mum and consecutive sections were alternately placed on two sets of slides. For cytological diagnosis and acquisition of embryonic contours, stained sections of the first series, termed 'working series', were scanned with the x 100 objective using 'Huge Image', a recently established image acquisition system. For acquisition of the contours of the resin block, adjacent unstained sections of the second series, termed 'reference series', were scanned with the x 5 objective. Thereafter, 'hybrid sections' were created which combined vectorized embryonic contours and cellular events taken from the working series with vectorized block contours taken from the reference series. For realignment, consecutive 'hybrid sections' were matched by best-fit of the block contours. Stacks of realigned 'hybrid sections' were shaped like truncated pyramids and, thus, reflected repeated 'trimming' of the resin block during the sectioning procedure. Among 266 'hybrid sections' at intervals of 8 gm, needed to reconstruct the brain of a 15-day-old embryo of Tupaia belangeri (Scandentia), internal fiducials were required five times for realigning a total of six adjacent truncated pyramids. Application of this method provided realistic reconstructions of the positions of apoptotic cells in the entire developing brain without the need of secondary introduction of external fiducials. (C) 2002 Elsevier Science B.V. All rights reserved."],["dc.identifier.doi","10.1016/S0165-0270(02)00247-9"],["dc.identifier.isi","000179968900006"],["dc.identifier.pmid","12468007"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/33903"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Elsevier Science Bv"],["dc.relation.issn","0165-0270"],["dc.title","Use of 'reference series' to realign histological serial sections for three-dimensional reconstructions of the positions of cellular events in the developing brain"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","86"],["dc.bibliographiccitation.issue","1"],["dc.bibliographiccitation.journal","Developmental Biology"],["dc.bibliographiccitation.lastpage","102"],["dc.bibliographiccitation.volume","278"],["dc.contributor.author","Washausen, Stefan"],["dc.contributor.author","Obermayer, Bastian"],["dc.contributor.author","Brunnett, Guido"],["dc.contributor.author","Kuhn, Hans-Jürg"],["dc.contributor.author","Knabe, Wolfgang"],["dc.date.accessioned","2018-11-07T11:25:44Z"],["dc.date.available","2018-11-07T11:25:44Z"],["dc.date.issued","2005"],["dc.description.abstract","Epibranchial placodes and rhombencephalic neural crest provide precursor cells for the geniculate, petrosal, and nodose ganglia., In chick embryos and in Tupaia belangeri, apoptosis, in rhombomeres 3 and 5 helps to select premigratory precursor cells and to segregate crest cell streams derived from the even-numbered rhombomeres. Much less is known about the patterns and functions of apoptosis in epibranchial placodes. We found that, in Tupaia belangeri, combined anlagen of the otic placode and epibranchial placode 1 transiently share a primordial low grade thickening with post-otic epibranchial placodes. Three-dimensional reconstructions reveal complementary, spatially, and temporally regulated apoptotic and proliferative events that demarcate the otic placode and epibranchial placode 1, and help to individualize three pairs of epibranchial placodes in a rostrocaudal sequence. Later, rostrocaudal waves of proliferation and apoptosis extend from dorsal to ventral parts of the placodes, paralleled by the dorsoventral progression of precursor cell delamination. These findings suggest a role for apoptosis during the process of neuroblast generation in the epibranchial placodes. Finally, apoptosis eliminates remnants of the placodes in the presence of late invading macrophages. (C) 2004 Elsevier Inc. All rights reserved."],["dc.identifier.doi","10.1016/j.ydbio.2004.10.016"],["dc.identifier.isi","000226680400008"],["dc.identifier.pmid","15649463"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/56692"],["dc.language.iso","en"],["dc.notes.status","final"],["dc.notes.submitter","Najko"],["dc.relation.issn","0012-1606"],["dc.title","Apoptosis and proliferation in developing, mature, and regressing epibranchial placodes"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","503"],["dc.bibliographiccitation.issue","6"],["dc.bibliographiccitation.journal","ANATOMY AND EMBRYOLOGY"],["dc.bibliographiccitation.lastpage","512"],["dc.bibliographiccitation.volume","207"],["dc.contributor.author","Knabe, Wolfgang"],["dc.contributor.author","Knerlich, F."],["dc.contributor.author","Washausen, Stefan"],["dc.contributor.author","Kietzmann, Thomas"],["dc.contributor.author","Siren, A. L."],["dc.contributor.author","Brunnett, G."],["dc.contributor.author","Kuhn, H. J."],["dc.contributor.author","Ehrenreich, Hannelore"],["dc.date.accessioned","2018-11-07T10:50:26Z"],["dc.date.available","2018-11-07T10:50:26Z"],["dc.date.issued","2004"],["dc.description.abstract","The expression patterns of erythropoietin (EPO) and its receptor (EPOR) were investigated in the midbrain and in adjacent parts of the synencephalon and hindbrain of embryonic C57Bl mice. On embryonic (E) day 8 (E8), virtually all neuroepithelial cells expressed EPOR. After neural tube closure, subsets of these cells downregulated EPOR. In contrast, radial glial cells were EPOR-immunolabeled from E11 onwards. Simultaneously, subpopulations of early developing neurons upregulated EPO and expressed HIF-1, known to transcriptionally activate EPO. Three-dimensional reconstructions revealed subpopulations of EPO-expressing neurons: (1) in the trigeminal mesencephalic nucleus (TMN), (2) at the rostral transition of the midbrain and synencephalon, (3) in the basal plate of the midbrain, (4) in the trigeminal motor nucleus, and (5) in the trigeminal principal sensory nucleus. In the rostral midbrain and synencephalon, EPO-immunoreactive neurons were attached to EPOR-expressing radial glial cells. The identity of radial glial cells was proven by their immunoreactivity for antibodies against astrocyte-specific glutamate transporter, brain lipid-binding protein, and nestin. From E12.5 onwards EPOR was downregulated in radial glial cells. Viable neurons of the TMN continued to express EPO and upregulated EPOR. Our findings provide new evidence that components of the EPO system are present in distinct locations of the embryonic brain and, by interactions between neurons and radial glial cells as well as among clustered TMN neurons, may contribute to its morphogenesis. Whether the observed expression patterns of EPO and EPOR may reflect EPO-mediated trophic and/or antiapoptotic effects on neurons is discussed."],["dc.identifier.doi","10.1007/s00429-003-0365-y"],["dc.identifier.isi","000220086500009"],["dc.identifier.pmid","14770308"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/48650"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Springer"],["dc.relation.issn","0340-2061"],["dc.title","Expression patterns of erythropoietin and its receptor in the developing midbrain"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","147"],["dc.bibliographiccitation.issue","2"],["dc.bibliographiccitation.journal","Journal of Neuroscience Methods"],["dc.bibliographiccitation.lastpage","158"],["dc.bibliographiccitation.volume","113"],["dc.contributor.author","Suss, M."],["dc.contributor.author","Washausen, Stefan"],["dc.contributor.author","Kuhn, H. J."],["dc.contributor.author","Knabe, Wolfgang"],["dc.date.accessioned","2018-11-07T10:32:29Z"],["dc.date.available","2018-11-07T10:32:29Z"],["dc.date.issued","2002"],["dc.description.abstract","Detailed knowledge of the spatial and temporal interactions of distinct cellular events and of the genes involved in their regulation is a precondition for the understanding of morphogenetic and pathogenetic processes. Here, how patterns of cellular events in large objects can be visualized with the help of the image acquisition system 'Huge Image' is demonstrated. Huge images are composed of a multitude of small images scanned with the highest light microscopical resolution. The system is equipped with a programmable autofocus device and permits precise and rapid cytological diagnosis. A vector-based three-dimensional (3-D) reconstruction method which, in future projects, will be combined with 'Huge Image', is applied to visualize dynamic interactions between macrophages and the occurrence of apoptotic neuroepithelial cells in the early developing forebrain of Tupaia belangeri (Scandentia). Proportionally correct meshwire surfaces of small and large objects are generated independently of each other. The combined reconstruction of cellular events and large embryonic surfaces can be carried out from only subsets of histological serial sections, and, compared with volume-based systems, with a much lower need for memory, The practicability of our approach is compared with recent other methods used to demonstrate apoptotic patterns. (C) 2002 Elsevier Science B.V. All rights reserved."],["dc.identifier.doi","10.1016/S0165-0270(01)00486-1"],["dc.identifier.isi","000173812000004"],["dc.identifier.pmid","11772436"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/44358"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Elsevier Science Bv"],["dc.relation.issn","0165-0270"],["dc.title","High resolution scanning and three-dimensional reconstruction of cellular events in large objects during brain development"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","584"],["dc.bibliographiccitation.issue","4"],["dc.bibliographiccitation.journal","The Journal of Comparative Neurology"],["dc.bibliographiccitation.lastpage","597"],["dc.bibliographiccitation.volume","502"],["dc.contributor.author","Knabe, Wolfgang"],["dc.contributor.author","Washausen, Stefan"],["dc.contributor.author","Happel, Nicole"],["dc.contributor.author","Kuhn, Hans-Juerg"],["dc.date.accessioned","2018-11-07T11:01:57Z"],["dc.date.available","2018-11-07T11:01:57Z"],["dc.date.issued","2007"],["dc.description.abstract","\"Starburst\" cholinergic amacrines specify the response of direction-selective ganglion cells to image motion. Here, development of cholinergic amacrines was studied in the tree shrew Tupaia belangeri (Scandentia) by immunohistochemistry with antibodies against choline acetyltransferase (ChAT) and neurofilament proteins. Starburst amacrines expressed ChAT much earlier than previously thought. From embryonic day 34 (E34) onward, orthotopic and displaced subpopulations segregated from a single cluster of immunoreactive precursor cells. Orthotopic starburst amacrines rapidly took up positions in the inner nuclear layer. Displaced starburst amacrines were first arranged in a monocellular row in the inner plexiform layer, and, with a delay of 1 week, they descended to the ganglion cell layer. Conversely, dendritic stratification of displaced amacrines slightly preceded that of orthotopic ones. Starburst amacrines expressed the medium-molecular-weight neurofilament protein (NF-M) from E34 to postnatal day 11 (P11) and coexpressed alpha-internexin from E36.5 to P11. Consequently, neurofilaments composed of alpha-internexin and NF-M may stabilize developing dendrites of starburst amacrines. During the first 2 postnatal weeks, subpopulations of anti-NF-M-labeled ganglion cells costratified with the preexisting dendritic strata of starburst amacrines in the ON sublamina, OFF sublamina, or both. Hence, anti-NF-M-labeled ganglion cells may include direction-selective ones. Thereafter, NF-M and a-internexin proteins disappeared from starburst amacrines, and NF-M immunoreactivity was lost in the dendrites of ganglion cells. Our findings suggest that NF-M and a-internexin are important for starburst amacrines and ganglion cells to recognize each other and, thus, contribute to the formation of early developing retinal circuits in the inner plexiform layer."],["dc.identifier.doi","10.1002/cne.21324"],["dc.identifier.isi","000246081800007"],["dc.identifier.pmid","17394160"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/51265"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Wiley-liss"],["dc.relation.issn","0021-9967"],["dc.title","Development of starburst cholinergic amacrine cells in the retina of Tupaia belangeri"],["dc.type","review"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","437"],["dc.bibliographiccitation.issue","3"],["dc.bibliographiccitation.journal","The Journal of Comparative Neurology"],["dc.bibliographiccitation.lastpage","457"],["dc.bibliographiccitation.volume","508"],["dc.contributor.author","Knabe, Wolfgang"],["dc.contributor.author","Washausen, Stefan"],["dc.contributor.author","Happel, Nicole"],["dc.contributor.author","Kuhn, Hans-Juerg"],["dc.date.accessioned","2018-11-07T11:15:04Z"],["dc.date.available","2018-11-07T11:15:04Z"],["dc.date.issued","2008"],["dc.description.abstract","Permanent ipsilaterally projecting axons approach the chiasmatic midline in rodents but are confined to lateral parts of the optic chiasm in marsupials. Hence, principally different mechanisms were thought to underlie axon pathway choice in eutherian (placental) and marsupial mammals. First evidence of diversity in eutherian chiasmatic architecture came from studies in the newborn and adult tree shrew Tupaia belangeri (Jeffery et al. [19981 J. Comp. Neurol. 390:183-193). Here, as in marsupials, ipsilaterally projecting axons do not approach the midline. The present study aims to clarify how the developing tree shrew chiasm is organized, how glial cells are arranged therein, and the extent to which the tree shrew chiasm is similar to that of marsupials or other eutherians. By using routinely stained serial sections as well as immunohistochemistry with antibodies against glial fibrillary acidic protein, vimentin, and medium-molecular-weight neurofilament protein, we investigated chiasm formation from embryonic day 18 (E18) to birth (E43). From E22 onward, ipsilaterally projecting axons diverged from contralaterally projecting axons in prechiasmatic parts of the optic nerve. They made sharp turns when arriving at glial arches found at the transition from the optic nerve to the chiasm. Thus, during the ingrowth period of axons, Tupaia belangeri and marsupials have specialized glial arrays in common, which probably help to deflect ipsilaterally projecting axons to lateral parts of the chiasm. Our observations provide new evidence of diversity in eutherian chiasmatic architecture and identify Tupaia belangeri as an appropriate animal model for studies on the mechanisms underlying axon guidance in the developing chiasm of higher primates."],["dc.identifier.doi","10.1002/cne.21694"],["dc.identifier.isi","000255004400004"],["dc.identifier.pmid","18335540"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/54285"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Wiley-blackwell"],["dc.relation.issn","1096-9861"],["dc.relation.issn","0021-9967"],["dc.title","Diversity in mammalian chiasmatic architecture: Ipsilateral axons are deflected at glial arches in the prechiasmatic optic nerve of the eutherian Tupaia belangeri"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]