Effects of intrathecal OB-Rb antisense oligonucleotides on the pain behavior induced in CCI rats. The thermal withdrawl latency TWL (A) and mechanical withdrawl threshold MWT (B) were measured after intrathecal administration of antisense nucleotides directed against the leptin receptor. The AS oligonucleotides were delivered intrathecally once daily for 6 days beginning on day 7 after CCI, as indicated by arrows. The TWL and MWT were tested 2 h after each administration of leptin. Data are shown as mean ± S.E.M, n = 6.