CNS activation by noxious heat to the hand or foot: Site-dependent delay in sensory but not emotion circuitry
CNS activation by noxious heat to the hand or foot: Site-dependent delay in sensory but not emotion circuitry
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DOI：
10.1152/jn.00326.2003
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发表时间：
2004-01-01
影响因子：
2.5
通讯作者：
Borsook, D
中科院分区：
文献类型：
--
作者：
Becerra, L;Iadarola, M;Borsook, D
最近，功能磁共振成像已被用作评价中枢神经系统对伤害性刺激的反应的新方法。在以前的研究中，长时间的有害热刺激施加到手背产生一个以上的血流动力学反应，是暂时隔离。这两个主要的反应分别显示了初级感觉区域（经典的疼痛回路）和涉及情感的区域（奖励/厌恶回路）的激活。在本研究中，我们分别对同一受试者的左足背和左手背施加相同的热刺激，并比较血流动力学反应，以评估传导距离对这两个隔离系统中CNS激活的影响。与手刺激后的反应相比，在对足部进行刺激后，初级感觉网络中的血流动力学反应在3.6+/-1.3 s的延迟后发生。在手部和足部刺激之间，奖赏/厌恶区域的血流动力学反应的相对延迟没有显著差异（0.6+/-2.1 s）。初级感觉系统中的这些结果与周围神经从手到脚的传导距离更大是一致的。观察到的反应内的奖励/厌恶的途径发生了相同的快速时间特性后，无论是手或脚的刺激支持的概念，参与评估厌恶刺激的电路是快速发作，可能是一个主要的保护机制的生存。
Recently, functional magnetic resonance imaging has been used as a novel method of evaluating the CNS response to noxious stimuli. In a previous study, a prolonged noxious thermal stimulus applied to the dorsum of the hand produced more than one hemodynamic response that was temporally segregated. The two major responses displayed activation in primary sensory regions (classic pain circuitry) and regions involved in emotion (reward/aversion circuitry), respectively. In the current study, we applied the same thermal stimulus separately to the dorsum of the left foot and the dorsum of the left hand in the same subjects and compared the hemodynamic responses to evaluate the effects of conduction distance on CNS activation within these two segregated systems. After stimulus delivery to the foot, the hemodynamic response in primary sensory networks occurs after a delay of 3.6+/-1.3 s as compared with the response after hand stimulation. The relative delay of the hemodynamic response in reward/aversion regions is not significantly different between hand and foot stimulation (0.6+/-2.1 s). These results within the primary sensory system are consistent with the greater conduction distance of the peripheral nerves from the hand versus the foot. The observation that the response within the reward/aversion pathways occurs with the same rapid temporal characteristics after either hand or foot stimulation supports the notion that the circuitry involved in the evaluation of aversive stimuli is rapid in onset and probably represents a major protective mechanism for survival.