title: Anterior cingulate cortical neuronal activity during perception of noxious thermal stimuli in monkeys.
abstract: It has been reported that the anterior cingulate cortex (ACC) has a variety of functions relating to pain as well as pain perception. However, the underlying mechanisms for those functions remain unclear. To elucidate the functional role of the ACC in pain perception and pain-related functions such as attention to pain and escape from pain, single neuronal activity was recorded from the ACC, and the behavioral correlates of this neuronal activity was studied. A total of 667 neurons were recorded from the ACC in awake behaving monkeys. Twenty-one had modulated activity during a heat-detection task. Eighteen of these increased their firing frequency following an increase in stimulus temperature, whereas three of them had decreased firing during heating of the face. Seventy-five percent of heat-evoked responses of heat-responsive ACC neurons were significantly depressed when monkeys detected the change in magnitude of illumination of a light presented on the front panel. The neuronal activity was significantly higher when monkeys escaped from a noxious heat stimulus than when the monkeys detected a small change in temperature (T2) above a larger initial shift (T1). No relationship between firing frequency and detection latency of the T2 stimulation was observed. These findings suggest that ACC nociceptive neurons are involved in attention to pain and escape from pain but not in the sensory discriminative aspect of pain.
authors.affiliation: Department of Physiology, Nihon University, School of Dentistry, 1-8-13 Kandasurugadai, Chiyoda-ku Tokyo, 101-8310. iwata-k@dent.nihon-u.ac.jp
authors.forename: Koichi
authors.initials: K
authors.lastname: Iwata
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kamo
authors.forename: Akiko
authors.initials: A
authors.lastname: Ogawa
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Tsuboi
authors.forename: Noboru
authors.initials: N
authors.lastname: Noma
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Mitsuhashi
authors.forename: Masato
authors.initials: M
authors.lastname: Taira
authors.forename: Noriaki
authors.initials: N
authors.lastname: Koshikawa
authors.forename: Junichi
authors.initials: J
authors.lastname: Kitagawa
mesh_terms: D000200:Action Potentials / Q000502:physiology / Q000528:radiation effects; D000818:Animals; D001931:Brain Mapping; D004307:Dose-Response Relationship, Radiation; D004924:Escape Reaction / Q000502:physiology / Q000528:radiation effects; D006179:Gyrus Cinguli / Q000166:cytology*; D006358:Hot Temperature; D008252:Macaca fascicularis; D009474:Neurons / Q000502:physiology*; D009619:Nociceptors / Q000502:physiology*; D010812:Physical Stimulation / Q000379:methods; D011597:Psychomotor Performance / Q000502:physiology; D011930:Reaction Time / Q000502:physiology / Q000528:radiation effects; D013697:Thermosensing / Q000502:physiology; D013997:Time Factors