L-AP4 (5-30 μg, intrathecal inhection 4-5 days) significantly increases the paw withdrawal threshold in response to application of von Frey filaments in eight nerve-ligated rats in a dose-dependent manner. Intrathecal administration of different doses of L-AP4 is not associated with any evident motor dysfunction[2].Intrathecal injection of 30 μg of L-AP4 does not significantly alter the paw withdrawal latency in these normal rats[2].Topical application of 5 to 50 μM L-AP4 to the spinal cord significantly inhibited the evoked response of neurons to touch, pressure, pinch, and von Frey filaments in a concentration-dependent fashion[2]. Animal Model: Rats.[2]