Dresden 2006 – wissenschaftliches Programm

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AKB: Biologische Physik

AKB 40: Poster Session II

AKB 40.65: Poster

Mittwoch, 29. März 2006, 16:30–19:30, P3

Capacitive Stimulation of Neurons by Opening Na⁺ Channels with Silicon Chips — •Ingmar Schoen and Peter Fromherz — Max Planck Institut für Biochemie, Abteilung Membran- und Neurophysik, 82152 Martinsried bei München

We demonstrate that opening Na⁺ channels by capacitive coupling with a silicon chip is a feasible, non-invasive method for neural stimulation in planar neuroelectronic devices.

Experiments were carried out with neurons from the pond snail Lymnaea stagnalis on silicon chips with HfO₂ as insulator. The cell was contacted with a patch pipette and ramps were applied to chip voltage. Capacitive coupling evoked an ionic current flow along the cleft in cell adhesion that led to an extracellular voltage drop therein. With a negative extracellular voltage, the adhesion membrane was depolarized. Voltage clamp experiments verified successful opening of ion channels and allowed for a detailed characterization of ionic currents and the optimization of Na⁺ influx. This charge inflow was capable of triggering action potentials in current clamp in a limited parameter range. In the case of positive extracellular voltage, the upper membrane was directly depolarized and sodium channel opening reliably led to action potentials.

This method provides a thorough understanding and control of stimulated neural excitation without malignant electroporation of the cell membrane or electrochemical reactions at the substrate surface.

[1] I. Schoen and P. Fromherz, Appl. Phys. Lett. 87, 193901 (2005).