Efficacy of Fu's Subcutaneous Needling on Sciatic Nerve Pain: Behavioral and Electrophysiological Changes in a Chronic Constriction Injury Rat Model

Summary

We present a protocol for using Fu's subcutaneous needling in a chronic constriction injury model to induce sciatic nerve pain in rats.

Abstract

Fu's subcutaneous needling (FSN), an invented acupuncture technique from traditional Chinese medicine, is used worldwide for pain relief. However, the mechanisms of action are still not fully understood. During FSN treatment, the FSN needle is inserted and retained in the subcutaneous tissues for a long duration with a swaying movement. However, challenges arise from maintaining a posture while manipulating FSN in animal models (e.g., rats) for researchers. Uncomfortable treatment can lead to fear and resistance to FSN needles, increasing the risk of injury and may even affect research data. Anesthesia may also affect the study results too. Hence, there is a need for strategies in FSN therapy on animals that minimize injury during the intervention. This study employs a chronic constriction injury model in Sprague-Dawley rats to induce neuropathic pain. This model replicates the pain induced by nerve injury observed in humans through surgical constriction of a peripheral nerve, mimicking the compression or entrapment seen in conditions such as nerve compression syndromes and peripheral neuropathies. We introduce an appropriate manipulation for easily inserting an FSN needle into the subcutaneous layer of the animal's body, including needle insertion and direction, needle retention, and swaying movement. Minimizing the rat's discomfort prevents the rat from being tense, which causes the muscle to contract and hinder the entry of the needle and improves the study efficiency.

Introduction

Neuropathic pain, defined as pain caused by nerve damage, is estimated to affect 6.9%-10% of the world's population, and the reported lifetime prevalence is 49%-70%^1,2. It is also considered to be one of the most difficult pain syndromes to manage. The use of pharmacological agents to manage neuropathic pain has yielded limited success as commonly prescribed pain medications like non-steroidal anti-inflammatory drugs and opioids have shown little efficacy in relieving this type of pain^3,4. There is therefore a great need to explore new treatment op....

Protocol

All procedures involving animal subjects were approved by the Institutional Animal Care and Use Committee (IACUC) of the Chang Bing Show Chwan Memorial Hospital, Changhua, Taiwan (111031) on October 2022 (Figure 1).

1. Preparation of animals

1. Purchase 48 maleSprague-Dawley (SD) rats (age: 8-10 weeks, weight: 250-300 g).
2. House rats individually in ventilated cages at 24 ± 2 °C and a 12-h dark and light cycle.
3. Feed rats a standard pellet diet with sterile drinking water ready to use, and provide soft bedding.

2. Grouping of a....

Results

Footprints and determination of the SFI
We examined the development of SFI in the CCI alone, CCI+FSN, and CCI+TENS groups (Figure 7). After 4 sessions of FSN and TENS treatments on day 7 for CCI surgery, the SFI in the CCI+FSN (-15.85 ± 3.46) and CCI+TENS (-29.58 ± 9.19) groups improved significantly compared to the CCI alone group (-87.40 ± 14.22). The improvement was significant in the CCI+FSN group compared to the CCI+TENS group (Figure 7A

Discussion

This study observes the effect of FSN treatment on neuropathic pain in rat CCI models. This study presents a protocol for SFI and electrophysiological testing to evaluate the therapeutic effects after FSN or TENS treatment. Additionally, it illustrates how to evaluate the functional recovery of the injured nerve using noninvasive behavioral tests and physiological measurements. Results showed that the FSN treatment after CCI-induced sciatic nerve pain showed significantly better improvement in all prognostic indicators t.......

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
Forceps	World Precision Instruments	14098
Fu’s subcutaneous needling	Nanjing Paifu Medical Science and Technology Co.		FSN needles are designed for single use. The FSN needle is made up of three parts: a solid steel needle core (bottom), a soft casing pipe (middle), and a protecting sheath (top).
Medelec Synergy electromyography	Oxford Instrument Medical Ltd.	034W003	Electromyogram (EMG) are used to help in the diagnosis and management of disorders such as neuropathies. Contains a portable two-channel electromyography/nerve conduction velocity system.
Normal saline (0.9%) 20 mL	Taiwan Biotech Co.,Ltd.	4711916010323	Lot: 1TKB2022
POLYSORB 4-0 VIOLET 30" CV-25	UNITED STATES SURGICAL, A DIVISION OF TYCO HEALTHC	GL-181
Retractor	COOPERSURGICAL, INC.(USA)	3311-8G
Rompun	Elanco Animal Health Korea Co. Ltd.	27668
SCISSORS CVD 90MM	BBRUAN	XG-LBB-BC101R
Transcutaneous Electrical Nerve Stimulation	Well-Life Healthcare Co.	Model Number 2205A	Digital unit which offers TENS. Supplied complete with patient leads, self-adhesive electrodes, 3 AAA batteries and instructions in a soft carry bag. Interval ON time 1–30 s. Interval OFF time 1–30 s.
Zoletil	VIRRBAC	8V8HA