A role of nerve growth factor in oligodendrocyte growth and differentiation of EAE affected rats.

We have previously shown that the level of nerve growth factor (NGF) undergoes significant changes in the cerebrospinal fluid of patients with Multiple Sclerosis and in the brain of rats affected by Experimental Allergic Encephalomyelitis (EAE). The functional significance of the endogenous disregulation of NGF is not known, though recent studies seem to suggest that NGF might be associated with the ability of oligodendrocytes (OLs) to produce and/or utilise NGF. The aim of the present study was therefore to investigate whether NGF is involved in the development and differentiation of cells of the subventricular zone (SVz) which arbors undifferentiated cells that can give rise to OLs. The results show that NGF injected into the brain of developing rats and of rats affected by EAE is retrogradely transported from the SVz to the brain parenchyma. These findings suggest that during the early phase of brain development and during EAE, NGF, along with other growth factors, is implicated in growth and/or differentiation of OLs and in protecting neuronal injury. The possible functional role of NGF in these events has been discussed.