Andressa Souza1, Daniel F Martins2, Liciane Fernandes Medeiros3, Catharina Nucci-Martins4, Thiago César Martins5, Aline Siteneski4, Wolnei Caumo6, Adair Roberto Soares Dos Santos4, Iraci L S Torres7. 1. Pain Pharmacology and Neuromodulation Laboratory: Preclinical Researches - Department of Pharmacology - Institute of Basic Health Sciences (ICBS) - Federal University of Rio Grande do Sul (UFRGS), Porto Alegre, RS 90050-170, Brazil; Post-Graduate Program in Medicine: Medical Sciences - UFRGS, Porto Alegre, RS 90035-003, Brazil; Animal Experimentation Unit - GPPG - Hospital de Clínicas de Porto Alegre, Porto Alegre, RS 90035-003, Brazil; Post-Graduate Program in Health and Human Development, Centro Universitário Unilasalle, Canoas, RS 92010-000, Brazil. 2. Laboratory of Experimental Neurosciences, Graduate Program in Health Sciences, University of South of Santa Catarina, Palhoça, SC 88137-270, Brazil. 3. Pain Pharmacology and Neuromodulation Laboratory: Preclinical Researches - Department of Pharmacology - Institute of Basic Health Sciences (ICBS) - Federal University of Rio Grande do Sul (UFRGS), Porto Alegre, RS 90050-170, Brazil; Post-Graduate Program in Medicine: Medical Sciences - UFRGS, Porto Alegre, RS 90035-003, Brazil; Animal Experimentation Unit - GPPG - Hospital de Clínicas de Porto Alegre, Porto Alegre, RS 90035-003, Brazil. 4. Pain and Inflammation Neurobiology Laboratory (LANDI), Federal University of Santa Catarina (UFSC), Florianópolis, SC 88040-900, Brazil. 5. Laboratory of Experimental Neurosciences, Graduate Program in Health Sciences, University of South of Santa Catarina, Palhoça, SC 88137-270, Brazil; Pain and Inflammation Neurobiology Laboratory (LANDI), Federal University of Santa Catarina (UFSC), Florianópolis, SC 88040-900, Brazil. 6. Pain Pharmacology and Neuromodulation Laboratory: Preclinical Researches - Department of Pharmacology - Institute of Basic Health Sciences (ICBS) - Federal University of Rio Grande do Sul (UFRGS), Porto Alegre, RS 90050-170, Brazil; Post-Graduate Program in Medicine: Medical Sciences - UFRGS, Porto Alegre, RS 90035-003, Brazil. 7. Pain Pharmacology and Neuromodulation Laboratory: Preclinical Researches - Department of Pharmacology - Institute of Basic Health Sciences (ICBS) - Federal University of Rio Grande do Sul (UFRGS), Porto Alegre, RS 90050-170, Brazil; Post-Graduate Program in Medicine: Medical Sciences - UFRGS, Porto Alegre, RS 90035-003, Brazil; Animal Experimentation Unit - GPPG - Hospital de Clínicas de Porto Alegre, Porto Alegre, RS 90035-003, Brazil. Electronic address: iltorres@hcpa.edu.br.
Abstract
BACKGROUND: Neuropathic pain is relatively common and occurs in approximately 6-8% of the population. It is associated with allodynia and hyperalgesia. Thus, non-pharmacological treatments, such as transcranial direct current stimulation (tDCS) may be useful for relieving pain. OBJECTIVES: This study aimed to investigate the antiallodynic effect of tDCS in a mice model of neuropathic pain, and the underlying neurotransmission systems that could drive these effects. METHODS: Male, Swiss mice, weighing 25-35 g, were subjected to partial sciatic nerve ligation (PSNL). Allodynia was assessed using a Von Frey filament (0.6 g). First, the behavioral time-course of these mice was assessed after 5, 10, 15 and 20 min of tDCS (0.5 mA). Second, the mice that underwent PSNL were assigned to either the tDCS (0.5 mA, 15 min) or tDCS sham group, and further assigned to receive either saline or a drug (i.e., naloxone, yohimbine, a-methyl-p-tyrosine, q-chlorophenylalanine methyl ester, caffeine, 1,3-dipropyl-8-cyclopentylxanthine, AM281, AM630, flumazenil, MK-801, or lidocaine). RESULTS: The antiallodynic effect of tDCS lasted 2 h and 4 h, after 10 min and 15 or 20 min of treatment, respectively (P < .001, P < .01, and P < .05, respectively). The antiallodynic effect of tDCS was associated with all the systems that were analyzed, i.e., the opioidergic (P < .01), adenosinergic (P < .001), serotonergic (P < .01), noradrenergic (P < .001), cannabinoid (P < .001), GABAergic, and glutamatergic (P < .001) systems. Lidocaine did not reverse the antiallodynic effect of tDCS (P > .05). CONCLUSION: The antiallodynic effect of tDCS was associated with different neurotransmitters systems; the duration of these after-effects depended on the time exposure to tDCS.
BACKGROUND:Neuropathic pain is relatively common and occurs in approximately 6-8% of the population. It is associated with allodynia and hyperalgesia. Thus, non-pharmacological treatments, such as transcranial direct current stimulation (tDCS) may be useful for relieving pain. OBJECTIVES: This study aimed to investigate the antiallodynic effect of tDCS in a mice model of neuropathic pain, and the underlying neurotransmission systems that could drive these effects. METHODS: Male, Swiss mice, weighing 25-35 g, were subjected to partial sciatic nerve ligation (PSNL). Allodynia was assessed using a Von Frey filament (0.6 g). First, the behavioral time-course of these mice was assessed after 5, 10, 15 and 20 min of tDCS (0.5 mA). Second, the mice that underwent PSNL were assigned to either the tDCS (0.5 mA, 15 min) or tDCS sham group, and further assigned to receive either saline or a drug (i.e., naloxone, yohimbine, a-methyl-p-tyrosine, q-chlorophenylalanine methyl ester, caffeine, 1,3-dipropyl-8-cyclopentylxanthine, AM281, AM630, flumazenil, MK-801, or lidocaine). RESULTS: The antiallodynic effect of tDCS lasted 2 h and 4 h, after 10 min and 15 or 20 min of treatment, respectively (P < .001, P < .01, and P < .05, respectively). The antiallodynic effect of tDCS was associated with all the systems that were analyzed, i.e., the opioidergic (P < .01), adenosinergic (P < .001), serotonergic (P < .01), noradrenergic (P < .001), cannabinoid (P < .001), GABAergic, and glutamatergic (P < .001) systems. Lidocaine did not reverse the antiallodynic effect of tDCS (P > .05). CONCLUSION: The antiallodynic effect of tDCS was associated with different neurotransmitters systems; the duration of these after-effects depended on the time exposure to tDCS.
Authors: Marcos F DosSantos; Aleli T Oliveira; Natália R Ferreira; Antônio C P Carvalho; Paulo Henrique Rosado de Castro Journal: Pain Res Manag Date: 2018-11-13 Impact factor: 3.037