Fig. 3. Antiallodynic effect, expressed as percent return to presurgery threshold after L5 and L6 spinal nerve ligation after intrathecal injection of 1 μg neostigmine at time 0 in females ( left, open symbols ) and males ( right, closed symbols ). Fifteen minutes before neostigmine, animals received intrathecal saline ( squares ), 10 μg atropine ( circles ), 10 μg mecamylamine ( triangles ), or 30 μg phentolamine ( diamonds ). Saline pretreatment is emphasized with the solid line. Values are mean ± SE for six animals. * P < 0.05 compared to saline by two-way analysis of variance.