清醒大鼠前扣带皮层神经元群的伤害性反应(英文)

Nociceptive responses of anterior cingulate cortical ensembles in behaving rats

目的 :利用多通道记录技术在清醒大鼠前扣带回 (ACC)记录神经元群的痛反应模式 ,以证实ACC在痛觉情绪编码中的作用。方法 :在 5只成年雄性SD大鼠的双侧ACC脑区植入微电极阵列 ,在大鼠术后清醒状态下给予尾部及四肢足底伤害性辐射热刺激 ,神经元的放电信号经由电缆和连接器传送至多通道记录系统。结果 :伤害性辐射热刺激在大鼠ACC引起以兴奋为主的反应 ,该反应持续时间较长 ,可能与痛情绪有关 ;刺激开始附近ACC神经元有与痛刺激相关的预期性反应 ,可能与准备逃避的动机有关 ;同侧和对侧肢体刺激引起的ACC神经元的反应差别不显著 ,表明神经元感受野大 ,不适合精确定位。结论

Objective: To confirm the role of anterior cingulated cortices (ACC) in the coding of pain affect by exploring the neural ensemble coding pattern within the anterior cingulate cortex in behaving rats with a multichannel recording technique. Methods: In five adult male Sprague Dawley rats, two arrays of eight stainless steel microwires were bilaterally implanted into ACC. Noxious radiant heat stimulation was applied to the tail, bilateral fore paws and hind paws of freely moving rats. Neuroelectric signals were obtained from the microwires and sent to a multichannel recording device via cables and connectors. The time stamps of neuronal activities were stored on a personal computer for off line analysis. Results:Noxious heat stimuli evoked predominantly excitatory and sustained neural activity within ACC, reflecting the processing of pain unpleasantness; pain related anticipatory responses could be seen near the stimulation start, indicating the behavioral preparation for escape; ACC neurons had broad receptive fields by showing quite similar pain related responses to stimuli on either side of the hind paw, suggesting that they are not eligible for the localization of a stimulus. Conclusion: ACC has played a major role in processing the affective motivational aspect of pain.