Primary culture of mouse embryonic spinal cord neurons: cell composition and suitability for axonal regeneration studies.

Primary culture is an effective experimental model to study molecular mechanisms that drive axonal regeneration after central nervous system injury. Nevertheless, the culture of spinal cord (SC) cells remains poorly characterized. Here, we have analysed the cell composition of a primary SC culture during its maturation. It was found that β3-tubulin (general neuronal marker) and nestin (a marker of neuronal stem cells) were both expressed at day 2 of culture in vitro. Surprisingly (given the use of differentiation-supporting culture medium), the number of nestin+ cells has significantly increased during the first week of cultivation. The cells that have expressed glial fibrillary acid protein, have appeared at the seventh day in vitro only, and their fraction has increased during the following cultivation. It was also revealed that the cells expressing the markers typical of commissural and motor neurons are present in SC culture at 14 days in vitro. At this age, the neurons have displayed the ability to repair injured neurites after mechanical damage. Altogether, our results identify primary culture of SC cells as a dynamically developing cell population that contains all main types of SC cells and is capable of self-repair. Therefore, the culture of mouse embryonic SC cells represents an adequate experimental model for studying cellular and molecular processes taking place in SC neurons after axonal damage in the absence of external inhibitors.