Метод викликаних потенціалів як перспективний напрямок дослідження ноцицепції у наркотизованих тварин

Abstract

The sensation of pain is a pathogenetic link in a wide range of diseases, and the study of nociception as its component is an important area of physiology and medicine. However, modern requirements for research conducted using laboratory animals require the search for new approaches to studying nociception and analgesia with minimizing the suffering of subjects in ethological testing and maximizing the transition to instrumental testing. We proposed the use of a standard formalin model of pain in combination with the recording of changes in somatosensory cortex potentials caused by electrical stimulation of efferents at the level of the forelimb. It was found that after subcutaneous injection of 0.30 ml of 4% formalin, the amplitude of evoked potentials increased. Under the conditions of the proposed testing design, both dosedependent and time-dependent effects of the formalin model of pain were observed in an anesthetized animal. The peculiarity of the obtained results was that the fixed somatosensory potentials of the brain in the S1 forelimb region showed sensitivity to the administration of a nociceptive agent in those areas of the body that topographically did not belong to the cortical representation of the forelimbs. This probably indicates the potential universality of this test approach. Thus, it was shown that evoked potentials in the forelimb representation of the primary somatosensory cortex demonstrate a clearly fixed response to painful stimulation in the formalin model of pain and can be used in studies of nociceptive and analgesic effects as a partial alternative to standard ethological testing.