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DTSTART:20180325T030000
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DTSTART:20171029T020000
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DTSTAMP:20260427T082551Z
UID:59f2c85eaed43497264309@ist.ac.at
DTSTART:20171113T100000
DTEND:20171113T110000
DESCRIPTION:Speaker: Sven Truckenbrodt\nhosted by Johann Georg Danzl\nAbstr
 act: Synaptic vesicles are arguably the most well-characterized organelle 
 model of cell biology. Their quantitative composition is known\, the synap
 tic environment has been reconstructed\, and their molecular interactions 
 are characterized in near-atomic detail. However\, like most organelles\, 
 synaptic vesicles are usually conceptualised as static\, not changing thei
 r behaviour over time. The assumption is that synaptic vesicles are produc
 ed and trafficked to the synapse\, where they are selected randomly for re
 lease/recycling until degradation ~4 days later. We tracked synaptic vesic
 les throughout this life-cycle\, using live antibody-tagging and correlati
 ve metabolic imaging (nanoSIMS and FUNCAT)\, and found that only young ves
 icles release neurotransmitter\, for ~12 hours. Combined pHluorin- and Ca2
 +-imaging further allowed us to determine that synaptic vesicle usage is l
 imited to ~200 release events during their entire life-span\, which is not
  exceeded even under increased demand. How is such a tight control of syna
 ptic vesicle usage achieved? Super-resolution STED microscopy revealed tha
 t ageing synaptic vesicles become contaminated with SNAP25 from the cell m
 embrane. On the vesicle\, SNAP25 interferes with the quantitatively scarce
  CSP-alpha\, hindering further release events. This inactivation is timed 
 to precede damage accumulation on synaptic vesicles\, likely to ensure tha
 t only pristine synaptic vesicles are employed in neurotransmission\, to m
 inimize damage-induced errors. This suggests that cells can track the func
 tional age of organelles and manage their usage through stochastic timer m
 echanisms. In addition to this functional investigation of synaptic vesicl
 es\, I will present a new way to achieve multi-colour super-resolution ima
 ging on conventional epifluorescence microscopes\, using a refined version
  of expansion microscopy\, termed X10. X10 allows a one-step expansion of 
 biological samples by ~10-fold\, achieving a resolution of ~25 nm\, and wi
 ll hopefully further advance the use of super-resolution microscopy in cel
 l biology.
LOCATION:Mondi Seminar Room 1\, Central Building\, ISTA
ORGANIZER:rsix@ist.ac.at
SUMMARY:Sven Truckenbrodt: The Life of an Organelle - Studying Synaptic Ves
 icles Through Life-span Tracking and X10 Expansion Microscopy
URL:https://talks-calendar.ista.ac.at/events/895
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