title: Frequency-dependent interaction of ultrashort E-fields with nociceptor membranes and proteins.
abstract: 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 (E(c) ) 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 E(c) as low as 16 V/cm (4000 Hz, 25 ms burst). There was no evidence of electroporation at field intensities near the E(c) 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 E(c) by about 50%.
authors.affiliation: Department of Oral and Maxillofacial Surgery and Diagnostic Sciences, Division of Neuroscience, College of Dentistry, University of Florida, Gainesville, FL 32610, USA.
authors.forename: Nan
authors.initials: N
authors.lastname: Jiang
authors.forename: Brian Y
authors.initials: BY
authors.lastname: Cooper
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism*; D004560:Electricity / Q000009:adverse effects*; D018274:Electroporation; D008297:Male; D009619:Nociceptors / Q000166:cytology* / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D015222:Sodium Channels / Q000378:metabolism*; D013997:Time Factors
chemical_list: D015222:Sodium Channels; D002118:Calcium