Sprouting inducing activity of human sera: low capacity in sera from patients with cranial polyneuropathy

Effect of cerebral neurite-stimulating protein on morphogenesis of organotypical culture of spinal ganglia

We have extracted a cationic protein with a molecular weight of 15,000 kdalton from the hemispheres of rat and bovine brain. Addition of the protein to the nutrient medium of the organotypical culture of chick embryo spinal ganglia results in a considerable (2-2.5 fold) increase in the growth zone of the explants. The neurite-stimulating effect of the protein is observed at a concentration of 10 ng/ml. We observed an intensive longitudinal growth of neurites, an increase in their amount per unit area, a considerable intensification of ramification, and formation of strong anastomoses, numerous dense plexuses, and arcades. Fasciculi of neurites covered with glia are formed. The cerebral neurite-stimulating protein is evidently one of the neuron-growth factors regulating development of the nervous system in the body.

Molecular events associated with increased regenerative capacity of the goldfish retinal ganglion cells following X-irradiation: decreased level of axonal growth inhibitors

In our previous work we established conditions to study the contribution of non-neuronal cells to the process of goldfish optic nerve regeneration. This issue has been studied successfully by adapting the use of X-irradiation to manipulate division of non-neuronal cells associated with the injured nerve. The regenerative capacity of the goldfish retinal ganglion cells was determined subsequent to the X-ray treatment. In this work we present an analysis of the molecular events associated with regeneration and enhanced regenerative capacity which follows X-irradiation. Under normal conditions the non-neuronal cells surrounding an intact nerve released axonal growth inhibitors, the level of which was only slightly sensitive to X-irradiation. In contrast, regenerating nerves showed a marked decrease in substances having an inhibitory effect on sprouting in vitro. Moreover, their level was significantly reduced following X-irradiation which was accompanied by increased accumulation of fibrous collagen adjacent to astrocytes. The alteration in the reciprocal relationship between the axon and the surrounding non-neuronal cells was also manifested by changes in the profile of labeled proteins released by the non-neuronal cells. The results of this work, therefore, indicate the sensitivity of retinal ganglion cells to the environment provided by the cells surrounding the regenerating fibers and thus may open a new perspective relating to the capacity of neurons to regenerate.

Systemic humoral factors participating in the course of spinal cord injury

Systemic humoral factors have been studied in traumatic, chronic and acute spinal cord injured patients. Antibodies specific to nervous system autoantigens were detected in a majority of the sera obtained from these patients, at different periods after injury. Limited in vitro sprouting of dorsal root ganglia in chicken embryos was observed in the presence of serum from these patients. The possible association between growth inhibiting factors and the presence of antibodies against nervous tissue autoantigens is discussed.