Cell culture of cryopreserved human fetal cerebral cortical and hippocampal neurons: neuronal development and responses to trophic factors

Past knowledge of the human brain at the cellular and molecular levels has come largely from studies of postmortem fixed tissue or by way of extrapolation from studies of lower mammalian species. The ability to study living human brain neurons would provide a new avenue for further insight into mechanisms operative in human brain development, function, and disease. The present study established procedures for the cryopreservation and culture of human fetal cerebral cortical and hippocampal neurons, and characterized the development of the cells in culture. The predominant cell type in both cortical and hippocampal cultures was pyramidal-like neurons that extended one long axon-like process and a few minor dendrite-like processes. Bipolar and stellate-like glia were also present in cultures from both brain regions. Fibroblast growth factor (FGF), but not nerve growth factor (NGF), enhanced long-term neuronal survival in both cerebral cortical and hippocampal cultures. Immunocytochemistry demonstrated the presence of both FGF- and NGF-like immunoreactivities in neurons and glia, from both cerebral cortex and hippocampus, suggesting that these endogenous growth factors may play roles in human fetal brain development. The ability to cryopreserve large numbers of viable dissociated human fetal brain neurons, and subsequently study them in cell cultures, provides new opportunities to understand dynamic aspects of the human brain at the cellular and molecular levels.