The Journal of Neuroscience, August 15, 1999, 19(16):6767-6773
Transistor Probes Local Potassium Conductances in the Adhesion
Region of Cultured Rat Hippocampal Neurons
Stefano
Vassanelli and
Peter
Fromherz
Department of Membrane and Neurophysics, Max-Planck-Institute for
Biochemistry, D-82152 Martinsried/München, Germany
Adhesion interactions of neurons in a tissue may affect the ion
conductance of the plasma membrane, inducing selective localization and
modulation of channels. We studied the adhesion region of cultured
neurons from rat hippocampus as a defined model where such effects
could be observed electrophysiologically, taking advantage of
extracellular recording by a transistor integrated in the substrate. We
observed the K+ current through the region of soma
adhesion under voltage-clamp and compared it with the current through
the whole cell. We found that the specific A-type conductance was
depleted, even completely, in the region of adhesion, whereas the
specific K-type conductance was enhanced up to a factor of 12. The
electrophysiological approach opens a new way to investigate targeting
of ion channels in the cell membrane as a function of adhesion processes.
Key words:
transistor; potassium; conductance; channel,
localization; A-type; K-type; adhesion
Copyright © 1999 Society for Neuroscience 0270-6474/99/19166767-07$05.00/0