Characteristics of neurite outgrowth from rat spinal ganglia: effects of serum and segmental level.

The outgrowth of neurites from spinal ganglia in tissue culture may be affected by many variables including medium constituents and the age of ganglia. If E15 rats were used, the rate of outgrowth from ganglion explants in response to nerve growth factor was independent of the cranial-caudal position from which the ganglia were derived. This contrasts with the cranial-to-caudal gradient present during embryonic development. The effect of serum on this outgrowth was also studied and ten of 17 lots of human placental serum, two of three lots of pooled human placental serum, and one of two lots of fetal calf serum significantly inhibited the outgrowth of neurites. This has relevance to the design of tissue culture studies and may be important in the interpretation of in vitro studies of disease mechanisms.