INCREASED NUMBER OF SCIATIC SENSORY NEURONS IN VITAMIN-E-DEFICIENT RATS

The number and morphometric characteristics of sciatic sensory neurons were studied in Vitamin-E-deficient rats. Horseradish peroxidase (HRP ) was injected into the sciatic nerves of normal and vitamin-E-deficie nt rats of the same age, and retrogradely labeled sensory neurons were counted and measured. The study was also carried out in rats that had previously undergone sciatic nerve crush, in order to observe the eff ects of axotomy on primary sensory neurons. In vitamin-E-deficient rat s the number of sciatic sensory neurons was significantly higher than normal, with an increase of about 30%, in agreement with a previous fi nding concerning total population of primary sensory neurons in lumbar dorsal root ganglia (DRGS) of vitamin-E-deficient rats. The increase involved the small cell classes in particular. Axotomy induced similar percentages of neuron loss in normal and in vitamin-E-deficient rats (about 40%). In the latter, death affected small cell classes in parti cular-that is, the same classes that had increased in number in vitami n-E-deficient rats by comparison with controls. These results, togethe r with previous findings, suggest that neurogenesis may occur in DRGs of vitamin-E-deficient rats.