BDNF AND NT-3 RESCUE SENSORY BUT NOT MOTONEURONS FOLLOWING AXOTOMY INTHE NEONATE

FOLLOWING axotomy of the sciatic nerve in the neonatal rat, there is l oss of almost half of the sensory neurones of the lumbar dorsal root g anglia (DRG) and a similar number of spinal motoneurones. Consistent w ith effects in vitro, the neurotrophins BDNF and NT-3 have previously been shown to afford partial rescue of motoneurones at 1 week followin g axotomy. Using stereological quantitative methods we show here that at the longer time point of 3 weeks,local application of BDNF or NT-3 to the proximal stump of a lesioned sciatic nerve failed to rescue mot eneurones (44% and 51% loss, respectively), but provided almost comple te rescue of the loss of 41% of DRG neurones seen in L4 and L5 of vehi cle-treated control animals.