Löwel, Siegrid

[["dc.bibliographiccitation.artnumber","e0154927"],["dc.bibliographiccitation.issue","5"],["dc.bibliographiccitation.journal","PLoS ONE"],["dc.bibliographiccitation.volume","11"],["dc.contributor.author","Bischof, Hans-Joachim"],["dc.contributor.author","Eckmeier, Dennis"],["dc.contributor.author","Keary, Nina"],["dc.contributor.author","Loewel, Siegrid"],["dc.contributor.author","Mayer, Uwe"],["dc.contributor.author","Michael, Neethu"],["dc.date.accessioned","2018-11-07T10:14:27Z"],["dc.date.available","2018-11-07T10:14:27Z"],["dc.date.issued","2016"],["dc.description.abstract","The visual wulst is the telencephalic target of the avian thalamofugal visual system. It contains several retinotopically organised representations of the contralateral visual field. We used optical imaging of intrinsic signals, electrophysiological recordings, and retrograde tracing with two fluorescent tracers to evaluate properties of these representations in the zebra finch, a songbird with laterally placed eyes. Our experiments revealed that there is some variability of the neuronal maps between individuals and also concerning the number of detectable maps. It was nonetheless possible to identify three different maps, a posterolateral, a posteromedial, and an anterior one, which were quite constant in their relation to each other. The posterolateral map was in contrast to the two others constantly visible in each successful experiment. The topography of the two other maps was mirrored against that map. Electrophysiological recordings in the anterior and the posterolateral map revealed that all units responded to flashes and to moving bars. Mean directional preferences as well as latencies were different between neurons of the two maps. Tracing experiments confirmed previous reports on the thalamo-wulst connections and showed that the anterior and the posterolateral map receive projections from separate clusters within the thalamic nuclei. Maps are connected to each other by wulst intrinsic projections. Our experiments confirm that the avian visual wulst contains several separate retinotopic maps with both different physiological properties and different thalamo-wulst afferents. This confirms that the functional organization of the visual wulst is very similar to its mammalian equivalent, the visual cortex."],["dc.identifier.doi","10.1371/journal.pone.0154927"],["dc.identifier.isi","000375675700076"],["dc.identifier.pmid","27139912"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/13251"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/40621"],["dc.notes.intern","Merged from goescholar"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Public Library Science"],["dc.relation.issn","1932-6203"],["dc.rights","CC BY 4.0"],["dc.rights.uri","https://creativecommons.org/licenses/by/4.0"],["dc.title","Multiple Visual Field Representations in the Visual Wulst of a Laterally Eyed Bird, the Zebra Finch (Taeniopygia guttata)"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","e11912"],["dc.bibliographiccitation.issue","8"],["dc.bibliographiccitation.journal","PloS one"],["dc.bibliographiccitation.lastpage","e11912"],["dc.bibliographiccitation.volume","5"],["dc.contributor.author","Keary, Nina"],["dc.contributor.author","Voss, Joe"],["dc.contributor.author","Lehmann, Konrad"],["dc.contributor.author","Bischof, Hans-Joachim"],["dc.contributor.author","Löwel, Siegrid"],["dc.date.accessioned","2019-07-09T11:53:19Z"],["dc.date.available","2019-07-09T11:53:19Z"],["dc.date.issued","2010"],["dc.description.abstract","BACKGROUND: The primary visual cortex of mammals is characterised by a retinotopic representation of the visual field. It has therefore been speculated that the visual wulst, the avian homologue of the visual cortex, also contains such a retinotopic map. We examined this for the first time by optical imaging of intrinsic signals in zebra finches, a small songbird with laterally placed eyes. In addition to the visual wulst, we visualised the retinotopic map of the optic tectum which is homologue to the superior colliculus in mammals. METHODOLOGY/PRINCIPAL FINDINGS: For the optic tectum, our results confirmed previous accounts of topography based on anatomical studies and conventional electrophysiology. Within the visual wulst, the retinotopy revealed by our experiments has not been illustrated convincingly before. The frontal part of the visual field (0 degrees +/-30 degrees azimuth) was not represented in the retinotopic map. The visual field from 30 degrees -60 degrees azimuth showed stronger magnification compared with more lateral regions. Only stimuli within elevations between about 20 degrees and 40 degrees above the horizon elicited neuronal activation. Activation from other elevations was masked by activation of the preferred region. Most interestingly, we observed more than one retinotopic representation of visual space within the visual wulst, which indicates that the avian wulst, like the visual cortex in mammals, may show some compartmentation parallel to the surface in addition to its layered structure. CONCLUSION/SIGNIFICANCE: Our results show the applicability of the optical imaging method also for small songbirds. We obtained a more detailed picture of retinotopic maps in birds, especially on the functional neuronal organisation of the visual wulst. Our findings support the notion of homology of visual wulst and visual cortex by showing that there is a functional correspondence between the two areas but also raise questions based on considerable differences between avian and mammalian retinotopic representations."],["dc.identifier.doi","10.1371/journal.pone.0011912"],["dc.identifier.fs","582119"],["dc.identifier.pmid","20694137"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/7274"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/60396"],["dc.language.iso","en"],["dc.notes.intern","Merged from goescholar"],["dc.relation.issn","1932-6203"],["dc.rights","Goescholar"],["dc.rights.uri","https://goescholar.uni-goettingen.de/licenses"],["dc.subject.mesh","Animals"],["dc.subject.mesh","Female"],["dc.subject.mesh","Male"],["dc.subject.mesh","Molecular Imaging"],["dc.subject.mesh","Optical Processes"],["dc.subject.mesh","Photic Stimulation"],["dc.subject.mesh","Songbirds"],["dc.subject.mesh","Superior Colliculi"],["dc.subject.mesh","Visual Cortex"],["dc.title","Optical imaging of retinotopic maps in a small songbird, the zebra finch."],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]