[MOS] April 20, 2010

[Zina Queen]

Seminar on

Modern Optics and Spectroscopy

Dye-less imaging of electrical activity in living cells using 
membrane eletromotility

Seungeun Oh, MIT

Tuesday, April 20, 2010

12:00 - 1:00 p.m.


Functional optical imaging techniques based on endogenous mechanisms  are
promising candidates for clinical use due to their low toxicity and
insensitivity to photo-bleaching. In neural tissue, electrical activity is
associated with optical signals originating from neuron or glia swelling, or
from changes of the plasma membrane's properties. These fast optical signals of
electrical activity are readily detectable in single invertebrate neurons or
nerve bundles. However, these signals have been elusive in single mammalian
neurons and their underlying mechanisms are not clear. We have developed a
novel optical microscope based on low-coherence interferometry to measure the
optical changes induced by electrical stimulation in individual cells. The
electrochemical characteristics, spatial structure and dynamical properties of
the optical signal show that the origin is membrane electromotility (MEM). The
signal is  generated in a two step process such that, through MEM, the
membrane potential first modulates the membrane tension, and then this tension
induces changes in the shape of the cell contingent on the mechanical
properties of the cytoplasm.


Grier Room, MIT Bldg 34-401
Refreshments served after the lecture
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