dc.contributor.advisor | Neher, Erwin Prof. Dr. | de |
dc.contributor.author | Hua, Yunfeng | de |
dc.date.accessioned | 2013-01-14T15:07:06Z | de |
dc.date.available | 2013-01-30T23:50:52Z | de |
dc.date.issued | 2012-09-25 | de |
dc.identifier.uri | http://hdl.handle.net/11858/00-1735-0000-000D-EF78-2 | de |
dc.identifier.uri | http://dx.doi.org/10.53846/goediss-1466 | |
dc.description.abstract | Im zentralen Nervensystem tritt die
Kommunikation zwischen Nervenzellen mittels chemischer Botenstoffe
(Neurotransmitter) hauptsächlich an den Synapsen auf. Bei
Stimulierung werden die Botenstoffe durch Ca2+-abhängige Exozytose
präsynaptischer Vesikel in den synaptischen Spalt freigesetzt, wo
sie postsynaptische Rezeptoren aktivieren. Um den Pool an Vesikeln
nach der Freisetzung von Botenstoffen wieder aufzufüllen, werden
Vesikelkomponenten nach der Exozytose wieder sortiert und durch
kompensatorische Endozytose in die Zelle aufgenommen. In dieser
Studie werden sowohl exogene cypHer-basierte und genetisch kodierte
GFP-basierte pH-Reporter verwendet, um den Vesikelzyklus in
kultivierten hippocampalen Neuronen der Ratte zu untersuchen. Durch
die Verwendung cyHher-konjugierter Antikörper gegen die luminalen
Domänen von Vesikelproteinen (z.B. Syt1) wird der Zyklus endogener
Vesikelproteine visualisiert. Zusätzlich ermöglicht die Verwendung
von CypHer-Antikörpern die Überwachung von in der Zellmembran
gestrandeten Vesikelproteinen, welche den sogenannten | de |
dc.format.mimetype | application/pdf | de |
dc.language.iso | eng | de |
dc.rights.uri | http://creativecommons.org/licenses/by-nc-nd/3.0/ | de |
dc.title | Study of synaptic vesicle cycling during exo- and endocytosis using optical approaches | de |
dc.type | doctoralThesis | de |
dc.title.translated | Studie des Vesikelzyklus während der Exo-und Endozytose mit optischen Methoden | de |
dc.contributor.referee | Neher, Erwin Prof. Dr. | de |
dc.date.examination | 2012-08-23 | de |
dc.subject.dnb | 570 Biowissenschaften, Biologie | de |
dc.subject.gok | WC 000 | de |
dc.description.abstracteng | In the central nervous system,
communication between nerve cells mainly occurs at synapses via
chemical neurotransmitters. Upon stimulation the transmitters are
released by Ca2+-triggered exocytosis of synaptic vesicles from
presynaptic terminal to the synaptic cleft, where they activate
postsynaptic receptors. In order to repopulate the vesicle pool for
further rounds of release, after exocytosis vesicle components need
to be resorted and retrieved from the surface by compensatory
endocytosis. In this study, both exogenous cypHer-based and
genetically encoded GFP-based pH-switchable reporters are used to
investigate the vesicle cycling in cultured rat hippocampal
neurons. Using cypHer-conjugated antibodies against luminal domains
of vesicle proteins (e.g. Syt1), visualizing cycling of endogenous
vesicle proteins has been achieved. In addition, by monitoring
surface-stranded vesicle proteins, constituting the so-called
readily retrievable pool, using cypHer-antibody, it was clearly
demonstrated that upon stimulation stained Syt1 residing on the
presynaptic membrane rather than freshly exocytosed unlabeled ones
are preferentially retrieved to form fresh vesicles, indicating an
active participation of the surface pool in the vesicle cycling.
Furthermore, the existence of this surface pool is also
corroborated by the observation of surface-stranded Syt1 at the
synaptic periphery, which is generally identified as the site of
endocytosis. These evidences indicate that exocytosis and
subsequent compensatory endocytosis of vesicles are driven in
parallel from the vesicle pool and the surface pool, respectively.
Since the surface pool is repopulated by newly exocytosed vesicle
components, fast translocation of vesicle proteins from presynaptic
center towards the periphery is expected. To explore potential
roles of this translocation in synaptic transmission,
dynamin-inhibitor Dynasore was applied to induce protein crowding
by blocking endocytosis. Under influence of this drug a clear
release depression was observed during high frequency stimulation,
which was, however, absent under control conditions. Based on this
observation, it is concluded that functional block of previously
used release sites rather than insufficient vesicle supply accounts
for the fast release depression after blocking endocytosis. This
finding implies an important role of dynamin for sustained synaptic
transmission at high rates beyond its well-known role in mediating
fission, a late step of endocytosis. | de |
dc.contributor.coReferee | Klingauf, Jürgen Prof. Dr. | de |
dc.contributor.thirdReferee | Egner, Alexander Prof. Dr. | de |
dc.subject.topic | Biology (incl. Psychology) | de |
dc.subject.ger | Vesikelzyklus | de |
dc.subject.ger | pH-Reporter | de |
dc.subject.ger | CypHer-Antikörper | de |
dc.subject.ger | Readily Retrievable Pool | de |
dc.subject.eng | vesicle cycling | de |
dc.subject.eng | pH-reporter | de |
dc.subject.eng | cypHer-antibody | de |
dc.subject.eng | readily retrievable pool | de |
dc.subject.bk | 42.12 | de |
dc.identifier.urn | urn:nbn:de:gbv:7-webdoc-3706-1 | de |
dc.identifier.purl | webdoc-3706 | de |
dc.affiliation.institute | Biologische Fakultät | de |
dc.identifier.ppn | 73391926X | de |