For this study, researchers compared animals that received placebo treatment with those that received only protective neurotrophic factors secreted by stem cells and those that had a transplant.

• 在这项研究中，研究者将接受安慰剂的动物，与仅接受由神经干细胞分泌的保护性神经营养因子以及接受移植的动物进行了对照。