Experiments were performed on adult, male Sprague-Dawley rats weighing 200-250 g. CCD was produced by surgically implanting stainless steel rods unilaterally into the intervertebral foramen at L4 and L5 as we previously described. In brief, the rats were anesthetized with sodium pentobarbital (40mg/kg, i.p.), the paraspinal muscles were separated from the mammillary and transverse processes and the intervertebral foramina of L4 and L5 exposed. A stainless steel L-shaped rod, 4 mm in length and 0.6 mm in diameter, was implanted into each foramen, one at L4 and the other at L5. Each insertion was guided by the mammillary process and transverse process.
As the rod was moved over the ganglion, the ipsilateral hind leg muscles typically exhibited one or two slight twitches. After surgery, the muscle and skin layers were sutured. An oral antibiotic, Augmentin, was administered after surgery in the drinking water for each rat (7.52 g in 500 ml) for seven days.
The presence of thermal hyperalgesia was determined by measuring foot withdrawal latency to heat stimulation of surface of hindpaw. The rats were tested on each of 2 successive days prior to surgery. Postoperative tests were conducted 1, 3, 5, 7, 10, 14 days after surgery and then once weekly for ~10 weeks in some rats for examining the long-term effects of B vitamins. For examining short-term effects, tests were conducted for up to 14 days and additional tests 2, 6, 12, 24 and 36 hours after injection of B vitamins on the third day after surgery.
The rats in different groups each received one of the following treatments via i.p. or i.t. I.p. treatments (0.1 ml/100g): (1) saline (0.9% NaCl); (2) B1 (5, 10 and 33 mg/kg, respectively)
Contact: Donna Krupa
American Physiological Society