心理所王錦琰副研究員與羅非研究員等人最近的一項(xiàng)關(guān)于痛覺預(yù)期的研究顯示,，痛覺預(yù)期能夠顯著增強(qiáng)傷害性刺激引起的神經(jīng)元放電以及痛覺內(nèi),、外側(cè)通路中的腦區(qū)內(nèi)及腦區(qū)間神經(jīng)活動(dòng)的相關(guān)性，說明內(nèi)側(cè)和外側(cè)痛覺系統(tǒng)對(duì)傷害性信息的加工都受到預(yù)期的調(diào)節(jié),。
無論是人還是動(dòng)物,，預(yù)期是痛覺的一個(gè)有效調(diào)節(jié)因素。已有研究證實(shí),，傷害性神經(jīng)元受到個(gè)體對(duì)于疼痛預(yù)期的調(diào)節(jié),。然而，還沒有研究考察痛覺預(yù)期對(duì)傷害性神經(jīng)元活動(dòng)以及中樞痛覺神經(jīng)網(wǎng)絡(luò)中功能聯(lián)結(jié)的影響,。因此,，該研究著重考察了痛覺神經(jīng)網(wǎng)絡(luò)中某些腦區(qū)內(nèi)與腦區(qū)間神經(jīng)元活動(dòng)的關(guān)系及信息流動(dòng)。研究使用聲音——激光條件化范式來建立大鼠的痛覺預(yù)期,，同時(shí)采用多通道記錄技術(shù)記錄了前扣帶回（ACC）,，丘腦背內(nèi)側(cè)核（MD）和初級(jí)軀體感覺皮層（S1）區(qū)的神經(jīng)元活動(dòng)。利用交互相關(guān)和偏定向相干分析方法來分析各記錄區(qū)域內(nèi)以及它們之間的功能聯(lián)結(jié),。結(jié)果表明,，在有預(yù)期的條件下，上述三個(gè)記錄腦區(qū)對(duì)傷害性刺激的反應(yīng)都有所增加,，而只有ACC神經(jīng)元對(duì)聲音信號(hào)的反應(yīng)增強(qiáng),。與沒有預(yù)期的條件相比，預(yù)期條件下各記錄腦區(qū)內(nèi)以及它們之間的神經(jīng)元活動(dòng)的相關(guān)性顯著增強(qiáng),，表明痛覺神經(jīng)網(wǎng)絡(luò)中神經(jīng)活動(dòng)的同步性增強(qiáng),。此外，從內(nèi)側(cè)痛覺傳導(dǎo)通路（ACC和MD）到外側(cè)痛覺傳導(dǎo)通路（S1）的信息流增加,，表明痛覺傳導(dǎo)過程中與情緒有關(guān)的神經(jīng)活動(dòng)可能會(huì)調(diào)節(jié)軀體感覺通路的神經(jīng)活動(dòng),。本研究為探索預(yù)期調(diào)節(jié)痛覺的腦機(jī)制提供了有力證據(jù)。
該研究已發(fā)表于《分子疼痛》（Molecular Pain）雜志上,。（生物谷Bioon.com）
生物谷推薦原始出處：
Molecular Pain,，2008, 4:34，Wang JY,，Luo F
Anticipation of pain enhances the nociceptive transmission and functional connectivity within pain network in rats
Jin-Yan Wang1 , Han-Ti Zhang2 , Jing-Yu Chang3 , Donald J Woodward3 , Luiz A Baccalá4 and Fei Luo1
1Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing, PR China
2Neuroscience Research Institute, Peking University, Beijing, PR China
3Neuroscience Research Institute of North Carolina, Winston-Salem, NC, USA
4Telecommunications and Control Engineering, Escola Politecnica, University of Sao Paulo, Brazil
Background
Expectation is a very potent pain modulator in both humans and animals. There is evidence that pain transmission neurons are modulated by expectation preceding painful stimuli. Nonetheless, few studies have examined the influence of pain expectation on the pain-related neuronal activity and the functional connectivity within the central nociceptive network.
Results
This study used a tone-laser conditioning paradigm to establish the pain expectation in rats, and simultaneously recorded the anterior cingulate cortex (ACC), the medial dorsal thalamus (MD), and the primary somatosensory cortex (SI) to investigate the effect of pain expectation on laser-induced neuronal responses. Cross-correlation and partial directed coherence analysis were used to determine the functional interactions within and between the recorded areas during nociceptive transmission. The results showed that under anticipation condition, the neuronal activity to the auditory cue was significantly increased in the ACC area, whereas those to actual noxious stimuli were enhanced in all the recorded areas. Furthermore, neuronal correlations within and between these areas were significantly increased under conditions of expectation compared to those under non-expectation conditions, indicating an enhanced synchronization of neural activity within the pain network. In addition, information flow from the medial (ACC and MD) to the lateral (SI cortex) pain pathway increased, suggesting that the emotion-related neural circuits may modulate the neuronal activity in the somatosensory pathway during nociceptive transmission.
Conclusion
These results demonstrate that the nociceptive processing in both medial and lateral pain systems is modulated by the expectation of pain.
