Blockade of nerve injury-induced LPA production. (a) Following pre-treatments of vehicle, MK-801, CP-99994, AACOCF3, BEL (each 10 nmol, i.t.) and minocycline (30 mg/ml, i.p.) before nerve injury, the ipsilateral spinal dorsal horn of each mouse was isolated at 3 h after injury. Levels of LPA species (18:1, 16:0, 18:0 LPA) were measured using such spinal cord preparations by MALDI-TOFMS. Besides, Lpar1- and Lpar3-deficient mice were also used to evaluate the LPA production at 3 h after injury. The capital letter “C” represents the control group (naive mice). The “veh”, “MK”, “CP”, “AA” and “mino” represent vehicle, MK-801, CP-99994, AACOCF3 and minocycline, respectively. (b) RT-PCR experiment was carried out to evaluate the expressions of LPA1 and LPA3 receptors in cultured mouse microglia and mouse spinal dorsal horn. (c) Thermal paw withdrawal test was performed at time-course points after nerve injury using wild-type or Lpar3-deficient mice. Results represent the threshold of latency (s) to thermal stimulus. “WT” represents the wide-type mice. Data represent means ± SEM from experiments using 3-8 mice. *p < 0.05, versus with the control group; #p < 0.05, versus with the vehicle-injury or injury-WT group.