We examined the influence of ultrashort pulses (USP) on sensory neurons. Single and high frequency bursts of 12 ns E-fields were presented to rat skin nociceptors that expressed distinct combinations of voltage-sensitive proteins. A single E-field pulse produced action potentials in all nociceptor subtypes at a critical threshold (Ec) of 403 V/cm. When configured into high frequency bursts, USP charge integrated to reduce the action potential threshold in a frequency and burst duration-dependent manner with Ec as low as 16 V/cm (4000 Hz, 25 ms burst).
There was no evidence of electroporation at field intensities near the Ec for nociceptor activation. USP bursts activated a late, persistent Ca++ flux that was identified as a dantrolene-sensitive Ca++-induced Ca++ release (CICR). Influx of Ca++ into the cell was required for the CICR and resulted in a reduction of the single pulse Ec by about 50%.
© 2010 Wiley-Liss, Inc.
Jiang, N. and Cooper, B.Y., 2011. Frequency‐dependent interaction of ultrashort E‐fields with nociceptor membranes and proteins. Bioelectromagnetics, 32(2), pp.148-163.
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