演講者: Dr. Ming-Tsung Tseng 曾明宗
講者單位: Graduate Institute of Brain and Mind Sciences National Taiwan University College of Medicine Taipei, Taiwan
演講title: Neuroimaging insights into the mechanisms of physiological and pathological pain

演講日期: 2014-09-23 Tuesday 14:00 ~ 16:00
演講地點(Seminar 地點) : 1st Conference Room, Auditorium and Activity Center (陽明大學活動中心第一會議室)


Abstract

In acute nociceptive pain, although neuroimaging studies of the past two decades have revealed a consistent pattern of brain activation in healthy subjects, such as the primary (SI) and secondary somatosensory cortices, insular cortex (IC), anterior cingulate cortex (ACC), and prefrontal cortex (PFC), a lack of studies investigating both peripheral and central nervous systems along the neural axis of pain impedes thorough understanding to the physiological and pathological mechanisms of pain. To circumvent this problem, I will present studies investigating the relationship between cutaneous sensory nerves and cerebral activations using functional MRI techniques in healthy subjects as well as pathological changes following peripheral nerve injuries in this talk. Similar but not identical to innocuous heat, painful heat stimulation elicited brain activations implicated in both sensory-discriminative and affective dimensions.
Activity in the IC and SI as well as their functional coupling paralleled pain perception, and IC-SI connectivity served as the functional representations of the small-diameter cutaneous afferents (i.e. peripheral nociceptive inputs) in the brain.
Intriguingly, only the sensory-discriminative but not affective aspects of pain declined as age increased, which was mediated by the activity in the IC and SI. In contrast to acute nociceptive pain, chronic pain sufferers displayed dissimilar cerebral activation patters. Following cutaneous nerve injury, diabetic patients with painful symptoms displayed augmented responses in the limbic and striatal structures, including the perigenual ACC, medial PFC, medial thalamus, anterior IC, and lentiform nucleus. In summary, neuroimaging techniques combined with peripheral investigations provide a new insight into the neurophysiology of pain circuits, and knowledge obtained from neuroimaging research sheds light on developing unique therapies by targeting the underlying specific pathways for each type of chronic pain in the future.