EFFECTS OF GDNF ON AXOTOMIZED SENSORY AND MOTOR-NEURONS IN ADULT RATS

Glial cell-line-derived neurotrophic factor (GDNF) is a potent neurotr ophic factor shown to rescue developing and adult motoneurons in vitro and in vivo from programmed and injury-induced cell death. To test wh ether GDNF would rescue adult mammalian sensory and motor neurons from physiological consequences of injury, the tibial nerve of rats was ax otomized and, after a 10 day delay to permit injury processes to proce ed, vehicle or GDNF was supplied directly to the nerve for 2 or 4 week s or GDNF intrathecally for 2 weeks. Conduction velocity (CV) of both sensory and motor axons declined during the initial 10 days, and even more so if then treated with vehicle. Treatment with GDNF resulted in marginal improvement of sensory axon CV. CV of motor axons recovered s ignificantly in a dose- and time-dependent manner. The results suggest that GDNF may have therapeutic potential in the treatment of peripher al neuropathies.