CHED 1275

In many studies it has been found that the amygdala contributes to inflammatory pain. Our laboratory has recently found that the amygdala also contributes to neuropathic pain behavior in the spared nerve injury (SNI) model of peripheral mononeuropathy. Learning how the amygdala functions in descending facilitation of neuropathic pain is very important. The amygdala is most known for its role in aversive learning. It has been reported that the amygdala's involvement in aversive learning is lateralized. Lateralization becomes very important in research in order to be affective in finding the actual pathways of neuropathic pain with a goal of normalizing pain. Lateralization also becomes very vital so that significant unilateral effects of neuropathic pain will not be overlooked. Specifically, the right amygdala has been implicated in inflammatory pain behavior, independent of the peripheral site of injury. The current experiment tested the hypothesis that the right amygdala is more involved in neuropathic pain behavior. Male Sprague-Dawley rats that had been given spared nerve injury were bilaterally implanted with cannulae aimed above the central nucleus of the amygdala. The central nucleus was targeted within the cannulation surgery. Cannulation placement is important and the cannulation is test for at the end of the experiment through a process called histology. There were two groups of animals: one group with SNI on the left side and the other group with SNI on the right side. One week after cannulation the animals received unilateral injections of lidocaine into either the left or right amygdala. Then the animals were tested for neuropathic pain behavior with the use of the von frey test, pin-prick test, and the acetone test. After the numbers from the testing were quantified the results were promising. The right amygdala had a very significant effect on neuropathic pain more than the left amygdala.