Localized membrane depolarizations and localized calcium influx during electric field-guided neurite growth.
Our study explores the mechanisms behind neurite galvanotropism. Using phase, differential interference contrast and ratiometric fluorescence microscopy, we reveal four responses of N1E-115 mouse neuroblastoma cells to 0.1-1.0 mV/microns uniform DC electric fields: cathode-directed neurite initiation and elongation, cathode-biased growth cone filopodial protrusions, transient cathode-localized calcium increases, and persistent cathode-localized membrane depolarizations. These newly demonstrated events are temporally and spatially correlated, suggesting that they are causally related. The calcium increases are prevented by calcium channel blockers and by the removal of extracellular calcium. We therefore propose that the observed field-induced membrane depolarizations activate voltage-dependent calcium channels, resulting in cathode-localized calcium influx. This, in turn, may initiate the observed cathode-biased growth cone filopodial protrusions, followed by the cathode-directed neurite elongation.
Duke Scholars
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Related Subject Headings
- Tumor Cells, Cultured
- Tissue Distribution
- Pyridinium Compounds
- Osmolar Concentration
- Neurology & Neurosurgery
- Neurites
- Microscopy, Interference
- Membrane Potentials
- Intracellular Membranes
- Electrophysiology
Citation
Published In
DOI
ISSN
Publication Date
Volume
Issue
Start / End Page
Location
Related Subject Headings
- Tumor Cells, Cultured
- Tissue Distribution
- Pyridinium Compounds
- Osmolar Concentration
- Neurology & Neurosurgery
- Neurites
- Microscopy, Interference
- Membrane Potentials
- Intracellular Membranes
- Electrophysiology