The neurotrophins NGF and NT-3 reduce sensory neuronal loss in adult rat after peripheral nerve lesion

The effect of three different neurotrophins on axotomy-induced death of adu lt rat sensory neurons was examined. The ventral branch of the 13th spinal nerve was transected and the corresponding neurons in the 13th thoracic (T1 3) dorsal root ganglion (DRG) were pre-labelled with Fast Blue (FB). For a period of 4 weeks, animals received either no treatment, continuous intrath ecal infusion of phosphate buffer, nerve growth factor (NGF), neurotrophin- 3 (NT-3), or brain-derived neurotrophic factor (BDNF). Labelled neurons rem aining after this period were counted, Inert, or no treatment, resulted in extensive loss of the DRG neurons. BDNF application was virtually non-effec tive, while NGF or NT-3 resulted in a greater number of FB-labelled neurons compared to normal controls. This suggests that NGF and NT-3 are survival factors for adult sensory neurons with a therapeutic potential in periphera l nerve injuries. (C) 1999 Elsevier Science Ireland Ltd. All rights reserve d.