Evidence for Spinal Conditioning in Intact Rats

Prior work suggests that spinal systems are sensitive to the stimulus relationships that underlie Pavlovian conditioning. We studied this phenomenon in Sprague–Dawley rats by pairing a vibrotactile conditioned stimulus (CS) with a tailshock unconditioned stimulus (US). Experiment 1 showed that spinal rats exhibit differential conditioning, having longer tail-flick latencies on the tail-flick test during a CS that was paired with the US (conditioned antinociception). Experiment 2 showed that rats trained with the cord intact still exhibit differential conditioning after the cord is cut. This suggests that spinal learning contributes to behavioral plasticity in intact subjects.