[Effect of morphine on pain sensitivity after removal of the 1st and 2d somatosensory areas of the cerebral cortex in cats].

Behavioral experiments on adult cats were performed to study the development of morphine analgesia before and after ablation of the first (S1) and the second (S2) somatosensory cortex. It was shown that injection of morphine before ablation of the cortical areas leads to an equal increase of the nociceptive response thresholds on both sides of the body, predominantly at those levels of the conventional scale where the emotional affective component of pain is remarkable. It was also noted that after ablation of the S1 and S2 morphine exerts a different effect on changes in the nociceptive response thresholds. The role of the somatosensory cortical areas in an analysis of noxious signals is discussed.