Home Research Project Details A4 - Quantifying the spatio-temporal organization of action potential generation by scanning ion conductance microscopy
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A4 - Quantifying the spatio-temporal organization of action potential generation by scanning ion conductance microscopy

Christoph Schmidt and Andreas Neef

Scanning ion conductance microscopy (SICM) produces high-resolution images by scanning a sharp glass pipette across a sample, using the electric current through the sub-micron opening of the pipette as a feedback signal to achieve a constant distance between pipette tip and sample surface. Spatial resolution in the plane of the surface depends on the pipette opening and can be as high as a few tens of nanometers. This technique is increasingly used in cellular neuroscience, on the one hand, because the truly force-free scanning mode allows faithful morphological imaging of such delicate features as cellular membranes and stereocillia of cochlear hair cells. On the other hand, the electric feedback signal together with the precise spatial resolution predestines SICM for functional mapping of ion channels.

In this project, we will use SICM to image cultured neurons and measure extracellular fields at different locations during action potentials (see e.g. Holt and Koch). Extracellular potential profiles are better suited to obtain information on local channel densities than intracellular information (see Gold et al.). Cell-attached recordings (Neef et al.) from morphologically and immuno-histochemically identified areas will address the functional specialization of sodium channels within the axon initial segment.

Belongs to Group(s):
Bernstein Fellows, Cell Biophysics

Is part of  Section A 

Members working within this Project:
Neef, Andreas 
Schmidt, Christoph 

Selected Publication(s):