The influence of cerebrospinal fluid on the development of cerebral cortical cells

This thesis presents a study of the interaction between cerebrospinal fluid (CSF) and cerebral cortical cells isolated from fetal rat brains. The aim of the study was to determine whether fetal CSF has the potential to maintain primary cortical cells and support their proliferation and differentiation. In addition, initial protein analysis was carried out on CSF and showed changes in composition which may underlie the different potential of CSF from different ages. The study describes a method for the collection of contamination-free CSF from the fetal and early postnatal rat brain in addition to methods for culture of primary fetal cortical cells in media or CSF. Four significant outcomes of these studies can be listed: Firstly pre-natal El 8 to E21 and early post-natal P2 and P6 CSF can keep cerebral cortex cells alive with no addition of medium, growth factor(s) and serum. E l7 CSF appears unable to support survival of cells; Secondly, there is a remarkable difference in the stimulatory effects of CSF from different aged fetuses; Thirdly, there is also a remarkable difference in the response of the cells from different aged fetuses and; Fourthly notwithstanding the differences observed on cortical cells in culture, all ages of CSF were found to contain the important growth factors bFGF and TGF-p. Cerebral cortical cells cultured in CSF of their own age showed significant proliferation except for E17 and E20 cells which showed a significant reduction in cell numbers after the period in culture. In contrast P2 and P6 cells showed little change in cell number but showed more significant differentiation of the cells in culture. To test the interaction between CSF composition and cell potential, cells were grown in different ages of CSF Results showed that pre-natal El 8,E l9, E20, and E21 and early post-natal P2 and P6 CSF contain important molecules necessary for survival, proliferation and differentiation of cerebral cells, but not E17 CSF. Significant proliferation only occurred in El 8 and E19 CSF suggesting this is the critical period for generation of neurones for the developing cortex. Initial protein analysis of CSF showed that both bFGF and TGF-p exist in all ages of CSF investigated suggesting that these important growth factors are not responsible for the differences in effect of CSF on primary cortical cells in culture, even the apparent death of cells in E17 CSF. In conclusion: The data from this study suggests that CSF plays an important, if not vital role in the normal development of the cerebral cortex. CSF can be used to maintain both the viability of cortical progenitor cells and their age related proliferative potential in vitro. The effects of CSF demonstrated in this study may provide some explanation for the failure of recent attempts at neural stem cell transplant therapy since the factors in postnatal, adult CSF may prohibit survival or differentiation of these cells. Further understanding of the role of CSF in development should produce better strategies for such therapies through manipulation of CSF composition