Abstracts - Deutsche Zoologische Gesellschaft

174 Neurobiology PostersP NB.7 - ENDiminished plasticity of visual function and sensory maps after cortical stroke in miceFranziska Greifzu 1 , Silvio Schmidt 2 , Karl-Friedrich Schmidt 1 , Otto W. Witte 2 , Siegrid Löwel 11Institute of General Zoology and Animal Physiology, Friedrich-Schiller-University Jena; 2 Departmentof Neurology, Medical School, University of JenaStroke is a major cause of death and disability in the industrialized countries. It is an encouragingobservation that clinically most patients who do suffer from stroke recover to some degree from thedeficits which they incur. The most straightforward assumption is usually that this is due to plasticity.Many in vitro studies indicated that there is an increased plasticity in the perilesional zone of corticalinfarcts. In the present study we investigated in vivo the impact of a photothrombotically inducedcortical stroke on the plasticity of the neighbouring visual cortex after short periods of monoculardeprivation (MD). Visual function was analyzed behaviourally with a virtual optomotor system. Inaddition, visual cortical maps were recorded using intrinsic signal optical imaging. After 7 days ofMD, control animals showed a significant enhancement of visual acuity in the non-deprived eyeand a significant ocular dominance shift towards the open eye in the optical imaging experiments.In contrast, in animals with a cortical stroke, both the enhancement of visual acuity and the oculardominance shift were significantly lower. Thus in contrast to previous in vitro studies, our data ratherindicate that plasticity is diminished in the surround of a cortical infarct.P NB.8 - ENTranscriptionfactor CREB in pteromalide waspsSteffen Hagenbucher, Martin Blum, Daria Schurmann, Axel Schweickert, Johannes L.M. SteidleInstitut für Zoologie, Universität HohenheimThe process of learning can be separated in several distinct phases: the short-term memory, the intermediatememory (MTM) and the long-term memory (LTM). The LTM is the only memory phase thatdepends on transcriptional activity These processes are regulated by the transcriptionfactor CREB(cAMP response element-binding protein). CREB plays an important role in the function and survivalof the nervous system. There are several known isoforms of this protein and in Drosophilaand Aplysia it could be shown that one of these isoforms acts as a repressor of the LTM formation.The two pteromalid wasps Lariophagus distinguendus and Nasonia vitripennis show significantdifferences in the memory formation process. L. distinguendus needs only one learning experienceto form LTM, in N. vitripennis only a MTM is formed after one experience. To study the idea thatdifferences in CREB-isoforms are responsible for these findings we screened mRNA of the two speciesfor CREB isoforms, using different PCR techniques like RT-PCR and RACE-PCR. We foundthree CREB isoforms in N. vitripenns (NvCREB 1, NvCREB 2, NvCREB 3), but only two in L. distinguendus(LdCREB 1, LdCREB 2). Whereas NvCREB 1 and LdCREB 1 as well as LdCREB 2 andNvCREB 2 are homologues; NvCREB 3 seems to be exclusive for N. vitripennis. It is possible thatthis additional NvCREB isoform is involved in the slower LTM formation in N. vitripennis. Furtherstudies on the function of the CREB isoforms are necessary to prove this hypothesis.