Asymmetrical bipolar nanosecond electric pulse widths modify bipolar cancellation.

Area of Science:

• Biophysics
• Cellular Electrophysiology

Background:

• Bipolar (BP) nanosecond electric pulse (nsEP) exposure results in reduced calcium influx compared to unipolar (UP) nsEP.
• This phenomenon is known as bipolar cancellation (BPC).

Purpose of the Study:

• To investigate the parameters of BP nsEP that induce BPC.
• To determine if symmetrical pulse widths are essential for BPC.

Main Methods:

• Utilized nsEP with varying pulse polarities and durations.
• Performed spatiotemporal analysis of YO-PRO®-1 uptake across the plasma membrane.

Main Results:

• BPC can be achieved with asymmetrical pulse widths, contrary to prior understanding.
• A ↑900 nsEP followed by a shorter pulse demonstrated cancellation.
• A ↑300 nsEP followed by a longer ↓900 nsEP resulted in a loss of BPC.
• Asymmetrical nsEP exposures created distinct YO-PRO®-1 uptake patterns.

Conclusions:

• Symmetrical pulse widths are not strictly required for BPC.
• BPC may be governed by localized charging and discharging events across the cell membrane.