Dividing cells do lie in close proximity to blood vessels in the early embryonic stages, but the association is looser in postnatal stages, a possible indication that the BV scaffolding doesn��t play a major role in migration; however, trophic factors could be trapped by the blood vessels providing a migratory signal. Interestingly, compounds introduced into the nasal cavity of rats and mice appear in large concentrations in the OB and olfactory nerve, whereas other routes of KT182 administration do not have the same ability to penetrate the BBB. Cells were also successfully introduced into the nasal cavity of rats and mice and found to transport into both the olfactory bulb, with ����close association���� to the RMS, as well as to other parts of the cerebrum via circulation through the cerebrospinal fluid. In a rat Parkinson model, intranasally delivered mesenchymal stem cells were found to be widely distributed at four hours with multiple beneficial effects including reduction of inflammatory cytokines and higher levels of both thymidine hydroxylase and dopamine. Many of the methods used to define the RMS in rodents cannot be applied to human research. Literature points to the presence of a human RMS, but the function at various BMS-195614 stages of development remains to be clarified. Analysis of human fetal brains has shown a ventral extension of the anterior horn of the lateral ventricles that is analogous to the rodent RMS. Additionally, the distribution of doublecortin positive cells in human fetal brains indicates similarities in rodent and human neuroblast migration. Most attention has focused on the caudal to rostral migration of neuroblasts within the RMS. Data shows that intranasal administration of small peptides such IGF-I and EPO produce high CNS concentrations in as short as twenty minutes, suggesting the existence of a retrograde pathway. Little is known about a retrograde pathway or mechanism to explain this transport of peptides and cells in comparison to the better defined anterograde pathway.In the present study, we used a fluorescent tracer, CellTracker Green BODIPY, to determine whether intranasal administration provides a sufficient pathway for delivering drugs to the brain.