生物谷報道：王錦琰,、羅非等人最近的一項研究揭示了疼痛的反饋調節(jié)機制的特性,。疼痛是一種多維度現象，它在大腦中激活的是神經網絡,，而不是零星的腦區(qū),。人們越來越多的認識到，脊髓以上水平的腦機制在疼痛的表達和調節(jié)過程中發(fā)揮著重要作用,。王錦琰,、羅非等人通過觀察與疼痛相關的信息流和丘腦－皮層通路中的神經元的相互聯(lián)系研究了疼痛過程中皮層和丘腦在功能上的相互作用。研究者將微電極陣列植入大鼠四個不同的腦區(qū)：初級軀體感覺皮層(SI),，前扣帶回皮層(ACC),，丘腦腹后核(VP)和丘腦背內側核(MD)，在大鼠清醒狀態(tài)下,，給后肢足底施加輻射熱傷害性刺激,。結果顯示，在上述四個腦區(qū)記錄到大量的反應神經元,。研究者運用先進的生物信息分析手段——定向相干分析揭示了在傷害性刺激后腦內神經信息流的改變,，即從皮層(SI)到丘腦(VP)的信息量顯著增多，這表明在疼痛編碼過程中皮層對丘腦神經元有自上而下的影響,。同時,，交互相關分析顯示，在疼痛刺激下皮層和丘腦神經元之間的聯(lián)系顯著增強,，更為重要的是,，皮層神經元先于丘腦神經元放電，這與定向相干分析的結果非常的一致,?；谝陨习l(fā)現，王錦琰,，羅非等人提出,，痛覺信息在腦內傳遞的過程中是受到皮層－丘腦反饋機制調節(jié)的，這種調節(jié)主要體現在在疼痛的感覺(而非情緒)通路上,。這項研究對于認識疼痛的中樞調節(jié)機制作出了重要貢獻,，對于痛覺的形成和治療具有重要的理論和臨床意義。
研究結果論文Corticofugal influences on thalamic neurons during nociceptive transmission in awake rats. 已發(fā)表在《突觸》（）上,。
原始出處:
Synapse 2007, 61: 335-342
Research Article
Corticofugal influences on thalamic neurons during nociceptive transmission in awake rats
Jin-Yan Wang 1, Jing-Yu Chang 2, Donald J. Woodward 3, Luiz A. Baccalá 4, Ji-Sheng Han 5, Fei Luo 1 *
1Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing, China
2Department of Physiology and Pharmacology, Wake Forest University Health Science, Winston-Salem, North Carolina
3Neuroscience Research Institute of North Carolina, Winston-Salem, North Carolina
4Telecommunications and Control Engineering, Escola Politecnica, University of Sao Paulo, Sao Paulo, Brazil
5Neuroscience Research Institute, Peking University, Beijing, China
email: Fei Luo ([email protected])
*Correspondence to Fei Luo, Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, 10A Datun Road, Chaoyang District, Beijing 100101, People's Republic of China
Funded by:
National Natural Science Foundation of China; Grant Number: 30170307, 30370461, 30570577
Ministry of Education of China; Grant Number: 985-2-068-113
Ministry of Science and Technology of China; Grant Number: 2003CB515407
NIH; Grant Number: NS-43441, NS-40628, TW-06144, NS-19608
Keywords
cortex ?cingulate ?thalamus ?nociception ?crosscorrelation ?information flow
Abstract
Pain is a multidimensional phenomenon and processed in a neural network. The supraspinal, brain mechanisms are increasingly recognized in playing a major role in the representation and modulation of pain. The aim of the current study is to investigate the functional interactions between cortex and thalamus during nociceptive processing, by observing the pain-related information flow and neuronal correlations within thalamo-cortical pathways. Pain-evoked, single-neuron activity was recorded in awake Sprague-Dawley rats with a Magnet system. Eight-wire microarrays were implanted into four different brain regions, i.e., the primary somatosensory (SI) and anterior cingulate cortex (ACC), as well as ventral posterior (VP) and medial dorsal thalamus (MD). Noxious radiant heat was delivered to the rat hind paws on the side contralateral to the recording regions. A large number of responsive neurons were recorded in the four brain areas. Directed coherence analysis revealed that the amount of information flow was significantly increased from SI cortex to VP thalamus following noxious stimuli, suggesting that SI cortex has descending influence on thalamic neurons during pain processing. Moreover, more correlated neuronal activities indicated by crosscorrelation histograms were found between cortical and thalamic neurons, with cortical neurons firing ahead of thalamic units. On basis of the above findings, we propose that nociceptive responses are modulated by corticothalamic feedback during nociceptive transmission, which may be tight in the lateral pathway, while loose in the medial pathway. Synapse 61:335-342, 2007. © 2007 Wiley-Liss, Inc.
