Mouse spinal cord neurons in serum-free culture media: suitability for patch clamp studies on chemical and electrical excitability.

Methods were devised for the serum-free culture of spinal cord neurons derived from 12- to 13-day mouse embryos. Neurons exhibited good attachment if plated for 24 h on poly-d-lysine-coated dishes in the presence of serum. Cultures were subsequently fed with a serum-free medium consisting of minimum essential medium, Earle's salts and the N1 supplement, i.e. insulin, putrescine, transferrin, progesterone and selenium. After 3 weeks in vitro, growth and survival of neurons in this medium were comparable to results obtained using serum-supplemented medium. The presence of putrescine was not essential for the beneficial effects of N1, while insulin was required for long-term survival in serum-free media. Neurons maintained in serum-free media for 3 weeks retained aspects of electrical and chemical excitability characteristic of serum-grown cells.