The Effects of Two Different Exercise Programs on the Ultrastructural Features of the Sciatic Nerve and Soleus Muscle After Sciatic Crush

Abstract

Peripheral nerve injuries constitute a significant medical problem and the recovery is critically dependent on post-injury treatment. In this study, following sciatic nerve crush, we investigated the effects of a 4-week endurance training program (ET) and balance and coordination training program (BCT) on the ultrastructural features of the sciatic nerve and soleus muscle. The animals were randomly divided into Sham, non-trained (NT), ET, and BCT groups each of which included three animals. Ultra-thin cross and longitudinal sections (70-85 nm) were digitized and analyzed comparatively. The electron micrographic analysis of the sciatic nerve showed similar organelles features in the injury groups (myelin debris and swelling mitochondria). Nonetheless, the ET group presented better ultrastructural features as demonstrated by the greater predominance of rounded fibers and more defined organization in the myelinated axon bundles. In the soleus muscle's analyses, the injured groups demonstrated similar organelles' features (nucleus contained highly heterochromatic nuclei and smaller mitochondria). However, ET and BCT groups showed apparently enlarged myofibril cross-sectional areas and less collagen around muscle fibers, although, the ET group displayed reduced intermyofibrillar spaces and more closely aligned myofilaments when compared with the BCT group. Based on electron micrographic analysis, our findings suggest the presence of ultrastructural differences between the Sham, NT, and the trained groups. Therefore, exercise type seems to be responsible for producing some different positive features in the trained groups, while ET seems to have a more pronounced influence on the ultrastructural features of the sciatic nerve and the soleus muscle after a crush injury. Anat Rec, 300:1654-1661, 2017. © 2017 Wiley Periodicals, Inc.

The leptin receptor mutation of the obese Zucker rat causes sciatic nerve demyelination with a centripetal pattern defect

“…100,101,102,103] are segmental, unique and appear with a more injurious pattern than the ones found in this study or even than the ones described recently in rat sciatic with crushed injury. 104 In the largest branches of the obese rat nerves, most nerve fibers are myelinated 105 and bore injuries (not totaled in this report) across all the similarly processed obese nerve samples. In addition, some of the diamond knife traces obtained out of sectioning samples show tiny disruption of the myelin (Figures 5(c) and 14) but all other micrographs obtained the same knife, including lean nerves, are artifact-free and compared well with the micrographs found in other publications.…”

“…227 Additionally, traumatic crush defects found in a recent ultrastructural study, dealing with sciatic nerve in rodent, are different than our data. 228 Disturbances in the minor dense line with facing glycocalyx can be caused by some acquisition of excessive anionic repelling charges 198,223 out of a sequential, decreasing anionic amounts of residues (phosphorylated > sulfated > carboxylated). 168,[195][196][197][198][199]223 Repelling spaces can be revealed by clear, unstructured rifts in the fine morphology of the minor lines, where sciatic myelin external surfaces with excessive similar charges (sialic acid or associated) thus could cause other adherence faults, increasing disturbances in cooperative PG interactions.…”

Avaliação dos efeitos da natação como reabilitação pós-operatória na regeneração nervosa de ratos da linhagem Wistar submetidos a enxerto de nervos autólogos após lesão do nervo ciático

“…As lesões dos nervos periféricos são frequentes na prática clínica e representam um problema de saúde capaz de gerar incapacidade na população. 1 Os fatores etiológicos mais associados às lesões incluem: acidente automobilístico, lesão penetrante, e lesões relacionadas ao esporte. 2 Morfologicamente, ocorre um aumento no tecido conjuntivo intramuscular e atrofia muscular evidenciada pela diminuição na área da secção transversal das fibras musculares.…”

“…Apesar dos nervos periféricos possuírem a capacidade de regeneração, 5 a recuperação é criticamente dependente do tratamento pós-lesão. 1 Tratamentos não cirúrgicos, como o exercício físico, podem atuar na regeneração nervosa periférica. 4 O exercício físico executado no ambiente aquático induz efeitos fisiológicos que proporcionam benefícios aos sistemas cardiovascular, esquelético, muscular e nervoso que aumentam o processo de reparação tecidual.…”

Effects of two intensities of treadmill exercise on neuromuscular recovery after median nerve crush injury in Wistar rats

“…Treatments using exercise have been increasingly studied due to their positive results in the rehabilitation of PNS injuries and their role in neuroprotection and neuroregeneration (Armada-da-Silva et al, 2013; Cobianchi et al, 2017). Different exercise types, such as resistance training with weight (50 to 250 g) attached to the animals’ tails (Ilha et al, 2008), swimming exercise (20 to 40 min) with a progressive load of up to 10% body weight (Coradini et al, 2015), passive cycling of the limbs (Udina et al, 2011b) and treadmill exercises (Boeltz et al, 2013; Bonetti et al, 2017; English et al, 2011) have been tested to treat PNS injuries.…”