In vertebrate nervous system, formation of myelin sheaths around axons is essential for rapid nerve impulse conduction. However, the signals that regulate myelination in CNS remain largely unknown partially due to the lack of suitable in vitro models for studying localized cellular and molecular basis of axon-glia signals.
We utilize microfabrication technologies to develop series of CNS neuron culture microsystems capable of providing localized physical and biochemical manipulation for studying neuron-glia interaction and neural progenitor development.
First, a circular neuron-glia co-culture platform with one soma-compartment and one axon/glia compartment has been developed. The device allows physical and fluidic isolation of axons from neuronal somata for studying localized axon-glia interactions under tightly controlled biochemical environment. Oligodendrocyte (OL) progenitor cells co-cultured on isolated axons developed into mature-OLs, demonstrating the capability of the platform. The device has been further developed into higher-throughput devices that contain six or 24 axon/glia compartments while maintaining axon isolation. Increased number of compartments allowed multiple experimental conditions to be performed simultaneously on a single device. The six-compartment device was further developed to guide axonal growth. The guiding feature greatly facilitated the measurement of axon growth/lengths and enabled quantitative analyses of the effects of localized biomolecular treatment on axonal growth and/or regeneration. We found that laminin, collagen and Matri-gel promoted greater axonal growth when applied to somata than to the isolated axons. In contrast, chondroitin sulfate proteoglycan was found to negatively regulate axon growth only when it was applied to isolated axons.
Second, a microsystem for culturing neural progenitor cell aggregates under spatially controlled three-dimensional environment was developed for studies into CNS neural development/myelination. Dense axonal layer was formed and differentiated OLs formed myelin sheaths around axons. To the best to our knowledge, this was the first time to have CNS myelin expressed inside a microfluidic device. In addition, promotion of myelin formation by retinoic acid treatment was confirmed using the device.
In conclusion, we have developed series of neuron culture platforms capable of providing physical and biochemical manipulation. We expect they will serve as powerful tools for future mechanistic understanding of CNS axon-glia signaling as well as myelination.
| Identifer | oai:union.ndltd.org:tamu.edu/oai:repository.tamu.edu:1969.1/ETD-TAMU-2011-12-10511 |
| Date | 2011 December 1900 |
| Creators | Park, Jaewon |
| Contributors | Han, Arum, Li, Jianrong, Cheng, Xing, Kameoka, Jun, Ko, Gladys |
| Source Sets | Texas A and M University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis, thesis, text |
| Format | application/pdf |
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