Functional Na+ channels in cell adhesion probed by transistor recording

Area of Science:

• Biophysics
• Cell Biology
• Materials Science

Background:

• Cell membranes interact closely within tissues, making standard electrophysiology challenging.
• Investigating ion channel function in adherent cells requires novel methodologies.

Purpose of the Study:

• To characterize sodium channel (Na(V)1.4) activity in the cell adhesion area of HEK 293 cells.
• To utilize field-effect transistors (FETs) on a silicon substrate as a model system for studying adherent cell membranes.

Main Methods:

• HEK 293 cells were cultured on fibronectin-coated substrates.
• Field-effect transistors were employed to monitor ion channel activity in adherent cell membranes.
• Whole-cell current measurements were compared with transistor responses under voltage clamp.
• Alternating-current stimulation was used for calibration.

Main Results:

• Extracellular voltage at the cell-chip interface correlated with total membrane current.
• Sodium (Na+) channels in the fibronectin-mediated cell adhesion area exhibited normal functionality and density.
• The observed channel characteristics were indistinguishable from those in non-adherent membrane regions.

Conclusions:

• Ion channels, specifically Na+ channels, are functional and present in cell adhesion zones.
• This research establishes a foundation for studying ion channel dynamics in cell adhesion.
• The findings support the development of cell-based biosensors and neuroelectronic systems.