Some embodiments comprise methods, systems, and compositions to promote, improve and/or increase neuronal differentiation, oligodendrocyte differentiation, or neurological outcome or function in a patient in need thereof. Some embodiments also comprise the administration a composition comprising a pharmaceutically effective amount of one or more of a group comprising microRNA-146a, exosomes comprising microRNA-146a, a promoter of microRNA-146a expression, a microRNA-146a thymosin beta 4, and a phosphodiesterase 5 inhibitor to treat neurological conditions, diseases, or injuries in mammals, including in human beings.