Reaching task performance is associated to neuromuscular junction adaptations in rats with induced diabetes mellitus

Autor(es)

Y.C. Estrada-Bonilla ; P.A.T.S. Castro ^[2] ; G.L.F. Luna ^[3] ; A.B.A. Souza ^[4] ; G.S. Santos ^[5] ; T.F. Salvini ^[6] ; A.M.O. Leal ^[7] ; T.L. Russo ^[8]

• Tipo de documento: Artigo Científico
• Fonte: Brazilian Journal of Medical and Biological Research; v. 53, n. 7 2020-06-03.

Resumo

Upper limb performance is affected by diabetes mellitus (DM). Neuromuscular junction (NMJ) is a key structure to understand the relationship between performance and morphology in DM. The aim of the study was to analyze NMJ plasticity due to DM in an animal model and its relationship with the function of forelimbs in rats. Twelve Wistar rats were divided into control (C) and DM groups. Animals were trained to perform a grasping task, following procedures of habituation, shaping, and reaching task. DM was induced using streptozotocin. Forelimb neuromuscular performance for dexterity was evaluated one day before DM induction and five weeks following induction. After that, biceps, triceps, and finger flexors and extensors were removed. Connective tissue and muscle fiber cross-sectional area (CSA) were measured. NMJ was assessed by its morphometric characteristics (area, perimeter, and maximum diameter), using ImageJ software. Motor performance analyses were made using single pellet retrieval task performance test. Student’s t-test was used for comparisons between groups. A significant decrease in all NMJ morphometric parameters was observed in the DM group compared with the C group. Results showed that DM generated NMJ retraction in muscles involved in a reaching task. These alterations are related to signs of muscular atrophy and to poor reaching task performance. In conclusion, induced DM caused NMJ retraction and muscular atrophy in muscles involved in reaching task performance. Induced DM caused significantly lower motor performance, especially in the final moments of evaluation, when DM compromised the tropism of the muscular tissue. (AU)

• Processo FAPESP: 17/13655-6 - Sedentarismo e disfunção arterial em indivíduos pós-acidente vascular cerebral crônico
• Beneficiário: Thiago Luiz de Russo
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 15/21718-2 - Efeito do treino tarefa específica sobre adaptação muscular em ratos pós-isquemia cerebral
• Beneficiário: Paula Aiello Tomé de Souza Castro
• Modalidade de apoio: Bolsas no Brasil - Programa Capacitação - Treinamento Técnico
• Processo FAPESP: 13/21621-3 - Efeito do treino tarefa específica sobre adaptação muscular em gerbilos pós-acidente vascular encefálico isquêmico
• Beneficiário: Thiago Luiz de Russo
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 16/09750-0 - Efeito do treino tarefa específica sobre adaptação muscular em ratos pós-isquemia cerebral
• Beneficiário: Ana Beatriz do Anjos Souza
• Modalidade de apoio: Bolsas no Brasil - Programa Capacitação - Treinamento Técnico