Effects of bone marrow mononuclear cells on induction of axonal sprouting in cortico-cortical and cortico-striatal pathways in an animal model of cortical ablation

Maria De Fátima Dos Santos Sampaio,Messias Gonzaga Pereira,Norberto Cysne Coimbra,Arthur Giraldi-Guimarães,Camila Da Silva Lourenço

doi:10.1186/s13104-020-05116-z

Abstract

ObjectivesMany therapies have been proposed in order to investigate the mechanisms of neural repair associated with neurological diseases, including bone marrow mononuclear cells (BMMC) transplantation. However, there is evidence that some encephalic injuries are less responsive to neural repair, such as, for example, cortical ablation. On the other hand, some models of cortical ablation have shown functional recovery after BMMC transplantation. Thus, it is relevant to expand the knowledge of BMMC transplantation-induced neuroplasticity in animal models, considering a promising approach for the rehabilitation of patients with neurological diseases. Using an experimental model of cerebral cortex ablation in adult male Wistar rats, which is known to be poorly responsive to neuroplasticity, the aim of this study was to investigate the effects of BMMC on axonal sprouting in cortico-cortical and cortico-striatal pathways synaptic fields. An anterograde neurotracer was used to evaluate the distribution of axonal fibres.ResultsThe results showed that BMMC were not able to significantly induce axonal sprouting in the evaluated synaptic fields. Our results reinforced the idea that cortical ablation may be less responsive to neuroplasticity and the beneficial effects of BMMC therapy depend on the particularities of a neural microenvironment intrinsic to a given cortical lesion.

Highlights

The results showed that bone marrow mononuclear cells (BMMC) were not able to significantly induce axonal sprouting in the evaluated synaptic fields
Our results reinforced the idea that cortical ablation may be less responsive to neuroplasticity and the beneficial effects of BMMC therapy depend on the particularities of a neural microenvironment intrinsic to a given cortical lesion
Our findings showed that BMMC treatment did not induce an increase in axonal fibres in areas of the contralateral cortex and ipsilateral and contralateral neostriatum to the lesion of animals injured by cortical ablation

Summary

Introduction

Injuries to the motor cortex or cortico-spinal tracts interfere with motor control, making movement generation and coordination difficult and causing functional losses [1]. BMMC consists of hematopoietic progenitor cells and hematopoietic stem cells, lymphocytes, monocytes and a small number of mesenchymal stem cells (MSCs). They have shown beneficial effects by presenting the ability, among others, to release trophic factors and cytokines that favour neuroprotection and repair of injured tissue orchestrating a sensorimotor functional recovery [2–7]. In a previous study [14], our group investigated the effects of BMMC on functional recovery after focal cortical ablation in rodents. Given the scientific evidence about neuroplasticity [15–17], we considered the instigating cortical ablation model to evaluate the efficiency of BMMC in the induction of brain plasticity. This study aimed to investigate the effects of BMMC on induction of axonal sprouting in cortico-cortical and cortico-striatal projections synaptic fields. An anterograde neurotracer was used to evaluate the distribution of axonal fibres in synaptic fields of the contralateral neocortex and ipsilateral neostriatum to the lesion

Objectives

Results

Conclusion