Affiliations: The Fishberg Department of Neuroscience, Mount Sinai
School of Medicine, New York, NY, USA | Department of Pharmacology, Center for Biomedical
Neuroscience, University of Texas Health Science Center at San Antonio, TX,
USA | Current address: Department of Biomedical Engineering,
University of Texas at Austin, TX, USA | Department of Biology, Trinity University, San
Antonio, TX, USA
Note: [] Corresponding author: Zin Z. Khaing PhD, Department of
Biomedical Engineering, MC0800, 1 University Station, Austin TX, 78712, USA.
Tel.: +1 512 471 3672; Fax: +1 512 471 0616; E-mail: zin@che.utexas.edu
Abstract: Purpose: Stem cells and progenitor cells in the central nervous
system may have potential for therapeutic use in patients with degenerative
diseases or after injury. Neural precursor cells can be grown in culture in the
presence of mitogens as aggregates termed neurospheres (NSs), as a source of
proliferating progenitor cells. Withdrawal of mitogen and allowing the NSs to
adhere to a substrate is the conventional way to study the differentiation
potential of the progenitor cells propagated in NSs form. Here we asked if
differentiation occurs within NSs cultured in the normal manner, in the
presence of mitogen. Methods: We used non-passaged NSs derived from E13.5 mouse ventral
mesencephalon. Results: The NSs contained not only progenitor cells but also
phenotypically-differentiated neurons and glia, in the presence of mitogen.
Extracellular matrix molecules (fibronectin, laminin and collagen type IV) were
also detected within these NSs, which may aid in the differentiation of
progenitors inside the NSs. The cell types within NSs were also organized in a
way that the differentiated cells were found in the inner cell mass while
progenitors were found in the outer region. Additionally, the proportion of
differentiated cell types within the NSs was also affected by exposure to
different mitogens. Moreover, when placed together in to co-culture,
dissociated embryonic striatal and mesencephalic cells aggregated spontaneously
to form mixed NSs, enhancing the eventual differentiation into dopaminergic
neurons from progenitors within these NSs. Conclusion: Therefore, the NSs contained progenitor cells and
differentiated neurons and glial cells. In addition, NS culture system can be
used to study cellular differentiation in vitro in non-adherent conditions.
