Stem cell transplantation for enhancement of learning and memory in adult neurocognitive disorders.

The role of adult hippocampal neurogenesis in learning and memory is still incompletely understood. Ablation of neurogenesis with different methods produced equivocal results with respect to working memory in Morris water maze and radial arm maze experiments. Therefore, it is remarkable that in the past few years several investigators have found a positive impact on working memory after adding stem or progenitor cells to the hippocampus in various disease models. The literature on stem cell transplantation for adult neurocognitive disorders is reviewed in this article and attempted to be reconciled with current research on adult hippocampal neurogenesis.