Article
Electrophysiological properties of human neural stem cells during differentiation
Elektrophysiologische Eigenschaften von humanen neuronalen progenitoren Zellen während Differenzierung
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Authors
Published: | May 4, 2005 |
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Outline
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Objective
Restorative therapies based on transplantation of neural stem cells (NSC) are considered to be a promising treatment strategy for many neurodegenerative diseases. Considerable knowledge has been gained in recent years about the morphological maturation of these cells. By contrast, much less is known about their electrophysiological properties. In the present study we analysed changes in active and passive membrane properties of human fetal cortical stem cells during in vitro differentiation.
Methods
Cortical tissue was obtained from elective abortions until the 12th week of gestation, expanded in culture medium containing bFGF and EGF, and differentiated for 6 weeks under mitogen-free conditions. Standard patch-clamp whole-cell technique was applied on 70 cells. Afterwards the cultures were immunostained for lineage and phenotype-specific markers.
Results
Cells were divided in 6 groups in accordance to the numbCells were divided in 6 groups in accordance to the numbConclusions
The present study showed clear electrophysiological properties of mature neurons derived from NSC. NSC differentiated in this way could generate functional neurons and thereby serve as a source for cellular replacement therapy in models of neurodegenerative diseases. er of weeks they spent in vitro before the electrophysiological study. We observed an increase of the cell capacitance, most probably due to dendrite growth (4.42±0.75 pF at the 1st week to 9.43±1.19 pF at the 6th week, p=0.003). An increase in the maximal K+-current amplitude was also seen (248±48 pA to 1109±286 pA, p=0.009), which indicates higher expression of K+-channels. We further analyzed the activation and inactivation time course of K-currents, and observed that 26% of the cells showed strong inactivation similar to what was reported for rat cortical pyramidal cells. On the other hand, 74% showed fast activation and minimal inactivation resembling K+-currents of cortical interneurons. In addition, we noted that the activation time course becomes faster as the cells mature (time constant of 4.80±1.00 ms to 1.52±0.33 ms, p=0.01). Large Na- and K-currents and action potentials were observed only after 4 weeks in culture. Immunocytochemistry confirmed expression of MAP2, type III β-tubulin, calbindin and GABA.
Conclusions
The present study showed clear electrophysiological properties of mature neurons derived from NSC. NSC differentiated in this way could generate functional neurons and thereby serve as a source for cellular replacement therapy in models of neurodegenerative diseases.