Fig. 2. Reversal of clonidine's effect by BRL44408. Withdrawal threshold to von Frey filament probing was determined before and after perineural injection, at the site of previous nerve injury, of clonidine, 30 μg, alone (solid squares) or with the α^2A-adrenoceptor antagonist, BRL44408, 5 μg (open squares), 15 μg (solid circles), or 45 μg (open circles). Each point represents the mean ± SE of six animals. *P < 0.05 compared with clonidine alone.