Effect of GaAlAs Laser and Acupuncture Therapy at BL40 on Neuropathic Pain in Rats

(3) Korean Journal of Acupuncture, Vol 28, No. 2, pp. 37–47, 2011

Effect of GaAlAs Laser and Acupuncture Therapy at BL40 on Neuropathic Pain in Rats

Jung-A Lim, Woo-Seok Chae, Suk-Hee Lee, Sung-Ho Jeong, Dae-Hwan Youn, Chang-Su Na

Abstract

Objectives: We studied the effects of GaAlAs (808 nm) low-level laser therapy (LLLT) and of acupuncture theory (AT) at BL40 on neuropathic pain induced in rats by lumbar spinal nerve 5 ligation.

Methods: To produce the model of neuropathic pain, we ligated the lumbar spinal nerve 5 under isoflurane 2.5% anesthesia by using 6–0 silk thread. After neuropathic surgery, we examined the animals to determine if they exhibited the behavioral sign of allodynia. The allodynia was assessed by stimulating the medial malleolus with a von Frey filament or with acetone. Three weeks after the neuropathic surgery, GaAlAs (808 nm) LLLT and AT were applied at BL40 once a day for 6 days. We examined the withdrawal response of the neuropathic rats’ legs by using a von Frey filament or acetone stimulation. Also, the author examined c-Fos, nociceptin and nociceptin receptor in the midbrain central gray matter of neuropathic rats.

Results: The GaAlAs (808 nm) LLLT and AT at BL40 decreased the withdrawal response of mechanical allodynia as assessed with a von Frey filament in the LLLT group by 5 and 6 times and as assessed with acetone in the AT group and the LLLT groups by 6 times. LLLT and AT at BL40 decreased the c-Fos protein expression in both the AT and the LLLT groups. The 808-nm LLLT and AT at BL40 decreased the nociceptin protein and nociceptin receptor protein in the LLLT group.

Conclusion: We have noticed that GaAlAs (808 nm) LLLT and acupuncture at BL40 decreased mechanical allodynia in the model of neuropathic pain. c-Fos, nociceptin and nociceptin receptor expressions in the central gray matter of that group was also decreased. This study can be used as a basic resource for the study and the treatment of pain.

Key Words: neuropathic pain; GaAIAs (808 nm) low level laser therapy (LLLT); c-Fos; nociceptin; nociceptin receptor