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PRODID:-//Columba Systems Ltd//NONSGML CPNG/SpringViewer/ICal Output/3.3-
 M3//EN
VERSION:2.0
CALSCALE:GREGORIAN
METHOD:PUBLISH
BEGIN:VEVENT
DTSTAMP:20210210T162712Z
DTSTART:20210217T130000Z
DTEND:20210217T140000Z
SUMMARY:A water window on biochemistry & physics: membranes\, ions\, ion 
 channels\, and neuronal activity
UID:{http://www.columbasystems.com/customers/uom/gpp/eventid/}m18q-kh23nl
 r8-bqv0u2
DESCRIPTION:Join us for this PSI seminar with guest speaker Professor Syl
 vie Roke. Lipid cell membranes are essential for life: They are a dynami
 c compartmentalized environment\, a localized space for proteins to perf
 orm their functions\, and select what enters the cell. Although recogniz
 ed as an essential building block\, water is usually treated as a backgr
 ound for biology. However\, water is a crucial mediator of chemical chan
 ge and determines the structure of the membrane. The study of lipid memb
 ranes is generally pursued by following either a top-down approach\, int
 roducing labels to living cell membranes or a bottom-up approach with we
 ll-controlled but over-simplified membrane monolayer or supported membra
 ne models. In the first approach molecular level hydration information i
 s lost\, while in the second approach the connection with real bilayer m
 embranes is limited. Recent work in our laboratory offers an alternative
  path that ultimately envisions bringing together both top-down and bott
 om-up approaches. By using intermediate nano-\, micro- and macroscale fr
 eefloating membrane systems in combination with novel nonlinear optical 
 spectroscopy and imaging methods\, we advance the understanding of reali
 stic membranes on a more fundamental level\, yet allowing for the comple
 xity of living systems. In this presentation I will first introduce high
  throughput wide-field second harmonic imaging\, which enables the label
 -free imaging of interfacial (< 1 nm thick) water\, with a spatial resol
 ution of ~370 nm and using ~100 ms acquisition times per image. We obtai
 n information about the orientational order of water and use this interf
 acial response to create spatiotemporal membrane potential maps of free 
 standing lipid membranes in solution. These maps are then used to quanti
 fy divalent – membrane interactions\, which show surprisingly heterogene
 ous behavior that deviates from predictions by mean field. Finally\, I w
 ill show how water in operating ion channels can be SH imaged and unders
 tood\, and how this can be used to directly visualize neuronal activity 
 in brain cells.\n\nThis event will be taking place online and details on
  how to join will be made available shortly.
STATUS:TENTATIVE
TRANSP:TRANSPARENT
CLASS:PUBLIC
LOCATION:This event will take place online
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