Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Transcutaneous Electrical Nerve Stimulation (TENS) has been widely used by physical therapists for pain management, though other non-analgesic properties have been cited. A series of studies have shown that TENS acts through both central and peripheral mechanisms. However, little is known about the mechanisms of action of TENS. So, in order to improve the research on such mechanisms, this work aimed to identify brain areas activated by different protocols of TENS stimulation in non-hyperalgesic rats. Fos protein expression in neurons has been used as a marker of neural activity. A total of 15 male Wistar rats weighing between 250 to 350 g received a single administration of TENS with low (4 Hz) or high (100 Hz) frequency and sensory (absence of muscle contraction) or motor (muscle contraction) intensity of stimulation. Ninety minutes after stimulation, the animals were euthanized under general anesthesia and their encephalons were perfused and sectioned to perform the immunofluorescence for Fos technique. Then images were captured and analyzed. The animals were split into five groups (n=3, per group): control, whose animals did not received electrical stimulation, low frequency TENS at sensory level, low-frequency TENS at motor level, high frequency TENS at sensory level and high frequency TENS at motor level. After analyzing the images, a significant higher c-Fos expression was found in the electrically stimulated animals when compared to the control group at the following brain areas: preoptic area (p=0.003), insular cortex (p=0.01), motor cortex (p=0.009), prefrontal cortex (p=0.003), thalamic paraventricular nucleus (p=0.003), endopiriform cortex (p=0.01), inferior colliculus (p<0.005), entorhinal cortex (p.0.0003), secondary somatosensory cortex (p.0.0003) and olfactory tract (p.0.0003) in a manner dependent from both frequency of stimulation and intensity of current. Thus, one suggest that TENS activated several important encephalon regions, which are involved in neural function such as cognition, memory, cardiovascular regulation and motor control; however, we cannot restrict these areas as the only ones that are influenced by TENS stimulation. These results are of great relevance, because it open perspectives on new and different neurobiological actions of TENS and its possible clinical applicability and therapeutic efficacy for addressing clinical situations unrelated to analgesia, allowing wider direction for further studies. / A estimulacao eletrica nervosa transcutanea (TENS) e bastante utilizada para o controle da dor; no entanto, outras propriedades nao analgesicas tem sido citadas. Uma serie de estudos tem demonstrado que a TENS atua atraves de mecanismos perifericos e centrais. A fim de aprimorar as pesquisas sobre esses mecanismos, esse trabalho teve o objetivo de verificar as areas encefalicas ativadas pelo uso de diferentes protocolos de eletroestimulacao com TENS em ratos nao-hiperalgesicos. A imunodeteccao da proteina Fos em neuronios tem sido utilizada como marcador de atividade neural. Logo, um total de 15 ratos Wistar, pesando entre 250 a 350 g, receberam uma unica aplicacao de TENS, sendo utilizada com baixa (4 Hz) ou alta (100 Hz) frequencia de estimulacao e com intensidade em nivel sensorial (ausencia de contracao muscular) e motor (presenca de contracao muscular). Noventa minutos apos a eletroestimulacao, os animais foram eutanasiados sob anestesia e seus encefalos foram perfundidos e seccionados para realizacao de imunofluorescencia para proteina Fos. Posteriormente, imagens foram capturadas e analisadas. Os animais foram divididos em cinco grupos (n=3, por grupo): controle, cujos animais nao receberam nenhuma estimulacao eletrica; TENS de baixa frequencia em nivel sensorial, TENS de baixa frequencia em nivel motor, TENS de alta frequencia em nivel sensorial e TENS de alta frequencia em nivel motor. Apos analise das imagens, verificou-se um numero de celulas Fos positivas significativamente maior nos grupos eletroestimulados em comparacao ao grupo controle nas seguintes areas encefalicas: area preoptica (p=0,003), cortex insular (p=0,01), cortex motor (p=0,009), cortex pre frontal (p=0,003), nucleo paraventricular talamico (p=0,003), nucleo endopiriforme (p=0,01), coliculo inferior (p<0,005), cortex entorrinal (p.0,0003), cortex somatossensorial 2 (p.0,0003), nucleo supraoptico (p.0,0003) e trato olfatorio (p.0,0003). Entretanto, esta ativacao neuronal ocorreu de forma dependente da frequencia de estimulacao e da intensidade da corrente nas diferentes regioes encefalicas. Assim, conclui-se que a TENS ativou diversas regioes encefalicas importantes, associadas a funcao de cognicao, memoria, regulacao cardiovascular e controle motor; no entanto, nao se pode restringir essas areas como as unicas cujos neuronios sao ativados pela TENS. Esses resultados sao relevantes uma vez que disparam perspectivas quanto a novas e diferentes acoes neurobiologicas da TENS e sua possivel aplicabilidade e eficacia terapeutica para a abordagem de situacoes clinicas que nao relacionadas a analgesia, possibilitando a ampliacao do direcionamento para a realizacao de novos estudos.
| Identifer | oai:union.ndltd.org:IBICT/oai:ri.ufs.br:riufs/3973 |
| Date | 30 August 2013 |
| Creators | Guimarães, Elisama de Campos |
| Contributors | Santana, Josimari Melo de |
| Publisher | Pós-Graduação em Ciências Fisiológicas |
| Source Sets | IBICT Brazilian ETDs |
| Language | Portuguese |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, info:eu-repo/semantics/masterThesis |
| Format | application/pdf |
| Source | reponame:Repositório Institucional da UFS, instname:Universidade Federal de Sergipe, instacron:UFS |
| Rights | info:eu-repo/semantics/openAccess |
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