title: Dynamic behavior of cells within neurospheres in expanding populations of neural precursors.
abstract: Large-scale expansion of neural stem and progenitor cells will be essential for clinically treating the large number of patients suffering from neurodegenerative disorders such as Parkinson's disease. Other applications of neural stem cell technology include further research in areas such as neural development or drug testing. Neural stem cells can be grown in vitro as tissue aggregates known as neurospheres, and in the current study, experiments were performed to determine the spatial arrangement and behavior of the cells within the neurosphere structure. A protocol utilizing sulfonated lipophilic fluorescent dyes was developed to effectively label populations of neural stem and progenitor cells without compromising cell density during culture. Cells retained the labels for at least 7 days. Using the labeling protocol, we discovered that the cells within the neurospheres were mobile and, moreover, the cells on the periphery of the neurospheres could migrate into the center of the neurospheres. Most important, the mixing time of two merging neurospheres was observed to be the same order of magnitude as the neural stem cell doubling time (approximately 20 h). This study is the first to show that the neurosphere system is dynamic, and these results will serve as a stepping stone to more in-depth studies of the neurosphere microenvironment.
authors.affiliation: Pharmaceutical Production Research Facility (PPRF), Schulich School of Engineering, University of Calgary, 2500 University Drive N.W., Calgary, Alberta, Canada T2N 1N4.
authors.forename: Tony Y
authors.initials: TY
authors.lastname: Wang
authors.forename: Arindom
authors.initials: A
authors.lastname: Sen
authors.forename: Leo A
authors.initials: LA
authors.lastname: Behie
authors.forename: Michael S
authors.initials: MS
authors.lastname: Kallos
mesh_terms: D000818:Animals; D002452:Cell Count / Q000379:methods; D002465:Cell Movement / Q000502:physiology*; D049109:Cell Proliferation; D002478:Cells, Cultured; D004622:Embryo, Mammalian; D005434:Flow Cytometry / Q000379:methods; D005456:Fluorescent Dyes; D051379:Mice; D009474:Neurons / Q000502:physiology*; D013234:Stem Cells / Q000502:physiology*; D013997:Time Factors; D023822:Tissue Engineering / Q000379:methods*
chemical_list: D005456:Fluorescent Dyes