Browsing by Subject "Sciatic nerve"

Now showing 1 - 4 of 4
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    A modified chemical protocol of decellularization of rat sciatic nerve and its recellularization with mesenchymal differentiated Schwann-Like cells: Morphological and functional assessments
    (Universidad de Murcia. Departamento de Biología Celular e Histología, 2017) García Pérez, M.M.; Martínez Rodríguez, H.G.; López Guerra, G.G.; Soto Domínguez, A.; Said Fernández, S.L.; Morales Ávalos, R.; Elizondo Omaña, R.E.; Montes de Oca Luna, R.; Guzmán López, S.; Castillo Galván, M.L.; Mendoza Lemus, O.F.; Vílchez Cavazos, F.
    The functional reconstruction of large neural defects usually requires the use of peripheral nerve autografts, though these have certain limitations. As a result, interest in new alternatives for autograft development has risen. The acellular peripheral nerve graft is an alternative for peripheral nerve injury repair, but to date there is not a standardized chemical decellularization method widely accepted. The objective of this study was to propose a modified chemical protocol of decellularization of rat sciatic nerve and its recellularization in vitro with mesenchymal differentiated Schwann-like cells. After the transplantation, an evaluation of its regeneration was performed using morphological and functional tests. The study consisted of two phases; in phase 1, different concentrations and times of exposure of rat sciatic nerves to detergents were tested, to establish a modified chemical protocol for nerve decellularization. The chemical treatment with 3% triton X-100 and 4% sodium deoxycholate for 15 days allowed a complete decellularization whilst conserving the extracellular matrix of the harvested nerve. In phase 2, the decellularized and recellularized alografts were compared against autografts. The morphological analysis showed a higher positivity to specific myelin antibodies in the recellularized group compared to the autograft. There were no differences in this parameter between the control limb and the experimental limb (recellularized group). The functional analysis showed no statistical differences at week 15 in the Sciatic Function Index in the autograft group vs the other groups. This study sets the morphological and functional bases for posterior studies about nerve defects regeneration in humans.
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    Ghrelin and adipose-derived mesenchymal stromal cells improve nerve regeneration in a rat model of epsilon-caprolactone conduit reconstruction
    (Universidad de Murcia. Departamento de Biología Celular e Histología, 2017) Hernández Cortés, Pedro; Toledo Romero, Miguel Angel; Delgado, Mario; Gonzalez Rey, Elena; Gómez Sánchez, Rafael; Prados Olleta, Nicolás; Aneiros Fernández, José; Crespo Lora, Vicente; Aguilar, Mariano; Galindo Moreno, Pablo; O’Valle, Francisco
    Objective. Attempts have been made to improve nerve conduits in peripheral nerve reconstruction. We investigated the potential therapeutic effect of adipose-derived mesenchymal cells (ASCs) and ghrelin (GHR), a neuropeptide with neuroprotective, trophic, and developmental regulatory actions, on peripheral nerve regeneration in a model of severe nerve injury repaired with nerve conduits. Material and methods. The right sciatic nerves of 24 male Wistar rats were 10-mm transected unilaterally and repaired with Dl-lactic-ε-caprolactone conduits. Rats were then treated locally with saline, ASCs, or GHR. At 12 weeks post-surgery, we assessed limb function by measuring ankle stance angle and percentage muscle mass reduction and evaluated the histopathology, immunohistochemistry, ultrastructure, and morphometry of myelinated fibers. Main Results. Rats receiving GHR or ASCs showed no significant increased functional recovery in ankle stance angle (p=0.372) but a higher nerve area (p=0.015), myelin area (p=0.046) and number of myelinated fibers (p=0.012) in the middle and distal segments of operated sciatic nerves in comparison to saline-treated control animals. Conclusion. These results suggest that utilization of ghrelin or ASCs may improve nerve regeneration using Dl-lactic-ε-caprolactone conduits.
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    Region-specific response of central microglial cells to sciatic nerve demyelination through sensory and motor pathways
    (Universidad de Murcia, Departamento de Biologia Celular e Histiologia, 2024) Wu, Shuang; Su, Yuxin; Wang, Yuqing; Wang, Jia; Xu, Dongsheng; Liu, Yihan; Yang, Kunwu; Gao, Junhong; Cui, Jingjing
    Peripheral nerve injury can cause changes in microglial cells on the spinal dorsal and ventral horns. This region-specific response implies that central microglial cells could be activated through both sensory and motor pathways. In order to further determine how peripheral nerve injury activates central microglial cells through neural pathways, the sciatic nerve was selected as the target for neural tract tracing and demyelination. Firstly, we used cholera toxin subunit B (CTB) to map the central sensory and motor territories of the sciatic nerve. Secondly, we applied lysophosphatidylcholine to establish the model of sciatic nerve demyelination and examined the distribution of activated microglial cells via immunofluorescence with ionized calcium-binding adapter molecule 1. It was shown that CTB labeling included the transganglionically labeled sensory afferents and retrogradely labeled somata of motor neurons along the sensory and motor pathways of the sciatic nerve ipsilateral to the injection, in which sensory afferents terminated on the gracile nucleus, Clarke’s nucleus, and spinal dorsal horn, while motor neurons located on the spinal ventral horn. Consistently, after sciatic nerve demyelination, the activated microglial cells were observed in the same territories as CTB-labeling, showing shortened processes and enlarged cell bodies. These results support the idea that central microglia might be activated by signals from the demyelinated sciatic nerve through both sensory and motor pathways.
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    Short-Term Effects of Deliberate Subparaneural or Subepineural Injections With Saline Solution or Bupivacaine 0.75% in the Sciatic Nerve of Rabbits
    (Frontiers Media, 2020-05-12) Laredo Álvarez, Francisco Ginés; Belda Mellado, Eliseo; Soler Laguía, Marta; Gil Cano, Francisco; Murciano Pérez, José; Sánchez Campillo, Joaquín; Agut Giménez, Amalia; Anatomía y Anatomía Patológica Comparada
    Background: Ultrasound (US)-guided techniques for peripheral nerve blockade have revealed that intraneural injections are relatively frequent and not necessarily associated with neurological deficits. Objectives: To evaluate the short-term effects of deliberate injections performed under direct vision in two different sites of the sciatic nerve (ScN). Material and Methods: Seventy-two New Zealand white rabbits randomly assigned to one of four experimental groups (n = 18) were employed. All procedures were conducted at a proximal femoral level where the ScN incorporates the common peroneal nerve and the tibial nerve (TN). Fixed volumes of 0.5ml of saline solution (ES group) or bupivacaine 0.75% (EB group) were administered extrafascicularly inside the paraneurium of the ScN or intrafascicularly (IS and IB groups) under the epineurium of the TN. Cross-sectional area (CSA) and relative echogenicity (RE) of the entire ScN were determined by US before injections, after injections, and at 3 and 7 days. ScN samples were obtained for structural and ultrastructural histopathological studies. Proprioceptive, sensorial, and motor function were clinically evaluated on a daily basis. Results: The CSA of the ScN increased significantly immediately after injections when compared with pre-injection values in all groups (p < 0.05). The RE of the ScN decreased in relation to pre-injection values in all groups (p < 0.05). The CSA and RE of the ScN returned to normal values 7 days after injections in almost all groups. Injected nerves showed histological signs of mild perineural inflammation. Histopathological scores were not significantly different between groups (p > 0.05). The architecture of the ScN was preserved in all rabbits at 3 days and in 31/32 rabbits at 7 days. A focal area of damaged nerve fibers with degeneration of the axons and myelin sheath affecting the TN was observed in one rabbit of the IB group. Nerve function was not clinically impaired in any case. Conclusion: Despite the lack of severe nerve disruption observed in most rabbits, the evidence of a focal area of damaged nerve fibers in one rabbit injected intrafascicularly with bupivacaine confirms that intrafascicular injections should be avoided as they may increase the risk of nerve damage.