Due to their widely known therapeutic benefits, mesenchymal stem cells have been proposed as a novel treatment option for a wide range of diseases including Alzheimer's disease. To maximize these benefits, critical factors such as delivery route, cell viability, and cell migration must be accounted for. Out of the various delivery routes to the brain, the intracerebroventricular (ICV) route stands out due to the widespread distribution that can occur via cerebrospinal fluid flow. The major objective of this present study was to observe how altering cell concentration influences the migration and viability of human umbilical cord blood derived-mesenchymal stem cells (hUCB-MSCs), delivered via ICV injection, in the brains of wild-type (WT) mice. C3H/C57 WT mice were divided into three groups and were injected with 1 x 10(5) hUCB-MSCs suspended in varying volumes: high (3 mu l), middle (5 mu l), and low (7 mu l) concentrations, respectively. Lowering the concentration increased the migratory capabilities and elevated the viability of hUCB-MSCs. These results suggest that cell concentration can affect the physiological state of hUCB-MSCs, and thus the extent of therapeutic efficacy that can be achieved. (C) 2017 The Authors. Published by Elsevier Inc.