Fig. 1. Analgesic effects of intrathecal arachidonyl-2-chloroethylamide (ACEA) on bone cancer–related pain behavior. (  A ,  C , and  E ) Time courses of analgesic effects of intrathecal ACEA at the dose of 1.0 nmol. (  B ,  D , and  F ) Dose-response relationships of ACEA and the effects of AM251 (0.06 nmol) or AM630 (10 nmol) on ACEA (1 nmol)–induced analgesic effects. (  A and  B ) Effects of ACEA on spontaneous flinches. (  C and  D ) Effects of ACEA on limb use. (  E and  F ) Effects of ACEA on weight-bearing. Data of flinches are presented as means ± SD. Data of limb use score and weight-bearing score are presented as medians with first and third quartiles, and minimum and maximum values. *  P < 0.05  versus values at 0 min (before drug administration) in  A –C . *P < 0.05  versus vehicle in  D –F . n =6 in no-treatment group;  n = 7 in vehicle group;  n = 8 in the remaining groups.