Effects of external low intensity focused ultrasound on electrophysiological changes in vivo in a rodent model of common peroneal nerve injury

• Published in: Neuroscience Vol. 429; pp. 264 - 272
• Main Authors: Hellman, Abigail, Maietta, Teresa, Byraju, Kanakaharini, Park, Yunseo Linda, Liss, Andrea, Prabhala, Tarun, Neubauer, Paul, Williams, Emery, Burdette, Clif, Shin, Damian S., Ghoshal, Goutam, Nalwalk, Julia, Agrawal, Aira, Qian, Jiang, Pilitsis, Julie
• Format: Journal Article
• Language: English
• Published: United States Elsevier Ltd 01-03-2020
• Subjects: Animals; common peroneal nerve injury (CPNI); dorsal root ganglion (DRG); Ganglia, Spinal; Hyperalgesia; low intensity focused ultrasound (liFUS); nerve modulation in vivo; Peripheral Nerve Injuries; Peroneal Nerve; Rats; Rats, Sprague-Dawley; Rodentia; CPN; nerve modulation in vivo; liFUS; CPNI; VFF; DRG; common peroneal nerve injury (CPNI); HPT; low intensity focused ultrasound (liFUS); dorsal root ganglion (DRG); NCS; SNAPs
• ISSN: 0306-4522; 1873-7544
• DOI: 10.1016/j.neuroscience.2020.01.016

•Study of liFUS’s effect on electrophysiology in vivo.•liFUS results in decreased latency of sensory nerve action potentials.•No change was found in signal amplitude.
Non-invasive treatment methods for neuropathic pain are lacking. We assess how modulatory low intensity focused ultrasound (liFUS) at the L5 dorsal root ganglion (DRG) affects behavioral responses and sensory nerve action potentials (SNAPs) in a common peroneal nerve injury (CPNI) model. Rats were assessed for mechanical and thermal responses using Von Frey filaments (VFF) and the hot plate test (HPT) following CPNI surgery. Testing was repeated 24 h after liFUS treatment. Significant increases in mechanical and thermal sensory thresholds were seen post-liFUS treatment, indicating a reduction in sensitivity to pain (p < 0.0001, p = 0.02, respectively). Animals who received CPNI surgery had significant increases in SNAP latencies compared to sham CPNI surgery animals (p = 0.0003) before liFUS treatment. LiFUS induced significant reductions in SNAP latency in both CPNI liFUS and sham CPNI liFUS cohorts, for up to 35 min post treatment. No changes were seen in SNAP amplitude and there was no evidence of neuronal degeneration 24 h after liFUS treatment, showing that liFUS did not damage the tissue being modulated. This is the first in vivo study of the impact of liFUS on peripheral nerve electrophysiology in a model of chronic pain. This study demonstrates the effects of liFUS on peripheral nerve electrophysiology in vivo. We found that external liFUS treatment results in transient decreased latency in common peroneal nerve (CPN) sensory nerve action potentials (SNAPs) with no change in signal amplitude.