Effect of stimulation of nerve regeneration on posttraumatic neuronal survival in dorsal root ganglia.

The survival of neurons is a key condition for complete posttraumatic regeneration of the peripheral nerve. In experiments on rats we studied survival capacity of different neuronal subpopulations in L(IV)-L(V) dorsal root ganglia after ligation or transection and suturing of the sciatic nerve. Experiments with nerve ligation showed that IB4+ neurons are more sensitive to the injury than NF200+ neurons. By day 90 after ligation of the sciatic nerve IB4+ neurons were virtually not detected in the dorsal root ganglia. By day 90 after nerve transection the number of surviving NF200+ and IB4+ neurons decreased by 26.1 and 21.4%, respectively, in comparison with intact animals. Treatment with xymedon, a regeneration stimulator, led to a 48.5% increase in the number of surviving NF200+ neurons by day 30 after ligation of the nerve and a 50.7% increase by day 90. The number of surviving IB4+ neurons increased more than 8-fold by this term after ligation of the nerve and drug stimulation. Xymedon had a neuroprotective effect towards both neuron subpopulations, more intensely preventing apoptosis of IB4+ neurons.