title: After-effects of consecutive sessions of transcranial direct current stimulation (tDCS) in a rat model of chronic inflammation.
abstract: Transcranial direct current stimulation (tDCS) induces cortical excitability changes in animals and humans that can last beyond the duration of stimulation. Preliminary evidence suggests that tDCS may have an analgesic effect; however, the timing of these effects, especially when associated with consecutive sessions of stimulation in a controlled animal experiment setting, has yet to be fully explored. To evaluate the effects of tDCS in inflammatory chronic pain origin immediately and 24 h after the last treatment session, complete Freund's adjuvant (CFA) was injected (100 μl) in the right footpad to induce inflammation. On the 15th day after CFA injection, rats were divided into two groups: tDCS (n = 9) and sham (n = 9). The tDCS was applied for 8 days. The hot plate and Von Frey tests were applied immediately and 24 h after the last tDCS session. Eight 20-min sessions of 500 μA anodal tDCS resulted in antinociceptive effects as assessed by the hot plate test immediately (P = 0.04) and 24 h after the last tDCS session (P = 0.006), for the active tDCS group only. There was increased withdrawal latency in the Von Frey test at 24 h after the last session (P = 0.01). Our findings confirm the hypothesis that tDCS induces significant, long-lasting, neuroplastic effects and expands these findings to a chronic pain model of peripheral inflammation, thus supporting the exploration of this technique in conditions associated with chronic pain and peripheral inflammation, such as osteoarthritis.
authors: Pain Pharmacology and Neuromodulation, Animal Models Laboratory, Porto Alegre, Brazil. gabrielalaste@gmail.com
authors: Gabriela
authors: G
authors: Laste
authors: Wolnei
authors: W
authors: Caumo
authors: Lauren Naomi Spezia
authors: LN
authors: Adachi
authors: Joanna Ripoll
authors: JR
authors: Rozisky
authors: Isabel Cristina
authors: IC
authors: de Macedo
authors: Paulo Ricardo Marques
authors: PR
authors: Filho
authors: Wania Aparecida
authors: WA
authors: Partata
authors: Felipe
authors: F
authors: Fregni
authors: Iraci L S
authors: IL
authors: Torres
mesh_terms: D000818:Animals; D002908:Chronic Disease / Q000628:therapy; D016207:Cytokines / Q000378:metabolism; D004195:Disease Models, Animal; D004599:Electric Stimulation Therapy; D004566:Electrodes; D005620:Freund's Adjuvant / Q000633:toxicity; D006930:Hyperalgesia / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy; D007249:Inflammation / Q000139:chemically induced / Q000378:metabolism / Q000628:therapy*; D008297:Male; D010147:Pain Measurement; D017288:Pain Threshold; D051381:Rats; D017208:Rats, Wistar; D011930:Reaction Time; D050781:Transcranial Magnetic Stimulation
chemical_list: D016207:Cytokines; D005620:Freund's Adjuvant