Catalogo Articoli (Spogli Riviste)

OPAC HELP

Titolo:
Activation of the somatosensory cortex during A beta-fiber mediated hyperalgesia - a MSI study
Autore:
Baron, R; Baron, Y; Disbrow, E; Roberts, TPL;
Indirizzi:
Univ Calif San Francisco, Dept Neurol, San Francisco, CA 94143 USA Univ Calif San Francisco San Francisco CA USA 94143 ancisco, CA 94143 USA Univ Calif San Francisco, Dept Radiol, San Francisco, CA 94143 USA Univ Calif San Francisco San Francisco CA USA 94143 ancisco, CA 94143 USA Univ Kiel, Neurol Klin, D-24105 Kiel, Germany Univ Kiel Kiel Germany D-24105 Kiel, Neurol Klin, D-24105 Kiel, Germany Stadt Krankenhaus Kiel, Radiol Abt, Kiel, Germany Stadt Krankenhaus Kiel Kiel Germany aus Kiel, Radiol Abt, Kiel, Germany
Titolo Testata:
BRAIN RESEARCH
fascicolo: 1, volume: 871, anno: 2000,
pagine: 75 - 82
SICI:
0006-8993(20000714)871:1<75:AOTSCD>2.0.ZU;2-5
Fonte:
ISI
Lingua:
ENG
Soggetto:
INDUCED SECONDARY HYPERALGESIA; SPINOTHALAMIC TRACT NEURONS; EVOKED MAGNETIC-FIELDS; NERVE-STIMULATION; PERIPHERAL NEUROPATHY; CORTICAL NETWORK; HUMAN BRAIN; PAIN; RESPONSES; CAPSAICIN;
Keywords:
magnetic source imaging; C-nociceptor; sensitization; neuropathic pain; allodynia; human;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Life Sciences
Citazioni:
36
Recensione:
Indirizzi per estratti:
Indirizzo: Baron, R Univ Calif San Francisco, Dept Neurol, San Francisco, CA 94143 USA Univ Calif San Francisco San Francisco CA USA 94143 CA 94143 USA
Citazione:
R. Baron et al., "Activation of the somatosensory cortex during A beta-fiber mediated hyperalgesia - a MSI study", BRAIN RES, 871(1), 2000, pp. 75-82

Abstract

Objective: To investigate the neural activation in the primary somatosensory cortex (SI) that is induced by capsaicin-evoked secondary A beta-fiber-mediated hyperalgesia with magnetic source imaging (MSI) in healthy humans. Background: Dynamic mechanical hyperalgesia, i.e. pain to innocuous light touching, is a symptom of painful neuropathies. Animal experiments suggest that alterations in central pain processing occur so that tactile stimuli conveyed in A beta low threshold mechanoreceptive afferents become capable ofactivating central pain signalling neurons. A similar state of central sensitization can be experimentally produced with capsaicin. Methods: In six individuals the somatosensory evoked magnetic fields (SEFs) induced by non-painful electrical stimulation of A beta-afferents at the forearm skin were recorded. Capsaicin was injected adjacent to the stimulation site to inducesecondary dynamic A beta-hyperalgesia. Thereafter, the SEFs induced by theidentical electrical stimulus applied within the secondary hyperalgesic skin were analyzed. The electrical stimulus was subsequently perceived as painful without changing the stimulus intensity and location. Latencies, anatomical source location and amplitudes of SEFs during both conditions were compared. Results: Non-painful electrical stimulation of A beta-afferents induced SEFs in SI at latencies between 20 and 150 ms. Stimulation of A beta-afferents within the capsaicin-induced secondary hyperalgesic skin induced SEFs at identical latencies and locations as compared with the stimulation of A beta-afferents within normal skin. The amplitudes, i.e., the magnetic dipole strengths of the SEFs were higher during A beta-hyperalgesia. Conclusions: Acute application of capsaicin produces an increase in the excitability of central neurons, e.g., in SI. This might be due to sensitization of central neurons so that normally innocuous stimuli activate pain signalling neurons or cortical neurons might increase their receptive fields. (C) 2000Elsevier Science B.V. All rights reserved.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 20/01/20 alle ore 07:27:21