Etiane Micheli Meyer Callai1,2,3, Vanessa Leal Scarabelot1,2, Liciane Fernandes Medeiros1,2,4, Carla de Oliveira1,2,4, Andressa de Souza1,2,5, Isabel Cristina Macedo1,2, Stefania Giotti Cioato1,2,6, Fabrício Finamor1,2,6, Wolnei Caumo4, Alexandre da Silva Quevedo1,6, Iraci L S Torres1,2,3,4,6. 1. Pharmacology of Pain and Neuromodulation Laboratory: Preclinical Researches, Department of Pharmacology, Institute of Basic Health Sciences (ICBS), Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil. 2. Animal Experimentation Unit and Graduate Research Group, Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil. 3. Graduate Program in Biological Sciences: Physiology, ICBS, UFRGS, Porto Alegre, Brazil. 4. Postgraduate Program in Medical Sciences, School of Medicine, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil. 5. Post-Graduate Program in Health and Human Development, Centro Universitário Unilasalle, Canoas, Brazil. 6. Graduate Program in Biological Sciences: Pharmacology and Therapeutics, ICBS, UFRGS, Porto Alegre, Brazil.
Abstract
OBJECTIVE: Our objective was to evaluate the Transcranial direct current stimulation (tDCS) effect on facial allodynia induced by chronic constriction of the infraorbital nerve (CCI-ION) and on the brainstem levels of TNF-α, NGF, IL-10, and serum LDH in rats. METHODS: Rats were exposed to the CCI-ION model. Facial allodynia was assessed by von Frey filaments test at baseline, 3, 7, 10, and 14 days postsurgery and 24 hr and 7 days after the bimodal tDCS sessions for 20 min/day/8 days. RESULTS: Chronic constriction of the infraorbital nerve induced a significant decrease in the mechanical threshold 14 days after surgery. This effect was reversed by tDCS treatment, with the mechanical threshold returning to basal levels at 24 hr after the end of the treatment and it persisted for 7 days after the end of the treatment. tDCS also decreased LDH serum levels compared to those in the control group. There was an interaction between pain and treatment with respect to brainstem levels of NGF, TNF-α, and IL-10. CONCLUSION: Chronic constriction of the infraorbital nerve model was effective in establishing trigeminal neuropathic pain on 14 days after surgery, and tDCS reduced allodynia and LDH serum levels and promoted alterations in NGF, TNF-α, and IL-10 brainstem levels. Thus, we suggest that tDCS may be a potential therapy in the trigeminal pain treatment.
OBJECTIVE: Our objective was to evaluate the Transcranial direct current stimulation (tDCS) effect on facial allodynia induced by chronic constriction of the infraorbital nerve (CCI-ION) and on the brainstem levels of TNF-α, NGF, IL-10, and serum LDH in rats. METHODS:Rats were exposed to the CCI-ION model. Facial allodynia was assessed by von Frey filaments test at baseline, 3, 7, 10, and 14 days postsurgery and 24 hr and 7 days after the bimodal tDCS sessions for 20 min/day/8 days. RESULTS: Chronic constriction of the infraorbital nerve induced a significant decrease in the mechanical threshold 14 days after surgery. This effect was reversed by tDCS treatment, with the mechanical threshold returning to basal levels at 24 hr after the end of the treatment and it persisted for 7 days after the end of the treatment. tDCS also decreased LDH serum levels compared to those in the control group. There was an interaction between pain and treatment with respect to brainstem levels of NGF, TNF-α, and IL-10. CONCLUSION: Chronic constriction of the infraorbital nerve model was effective in establishing trigeminal neuropathic pain on 14 days after surgery, and tDCS reduced allodynia and LDH serum levels and promoted alterations in NGF, TNF-α, and IL-10 brainstem levels. Thus, we suggest that tDCS may be a potential therapy in the trigeminal pain treatment.