Electrophysiologic evidence for involvement of the pituitary region in opiate analgesia.

In the past, various reports have discussed the relationship between the pituitary and analgesia. The purpose of the present study was to explore the possible role of the pituitary region in the mediation of pain by opioids. Tooth pulp evoked potentials recorded from primary somatosensory cortex and from the pituitary region of rabbits were recorded before and after an injection of opiates. Tooth pulp evoked potentials recorded from the primary somatosensory cortex were markedly inhibited after admission of fentanyl, while the tooth pulp evoked potentials recorded from the pituitary region were facilitated. It is concluded that the pituitary region plays a role in the mediation of pain and that this area is involved in the mechanism of opiate analgesia.