Comparison of activity characteristics of the cuneate nucleus and thoracic spinal neurons receiving noxious cardiac and/or somatic inputs in rats.
Comparison of activity characteristics of the cuneate nucleus and thoracic spinal neurons receiving noxious cardiac and/or somatic inputs in rats.
复制标题
大鼠楔形核和胸椎神经元接受有害心脏和/或躯体输入的活动特征比较。
DOI：
10.1016/j.brainres.2010.05.081
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发表时间：
2010
期刊：
影响因子：
2.9
通讯作者：
Foreman,RobertD
中科院分区：
文献类型：
--
作者：
Qin,Chao;Goodman,MelanieD;Little,JanineM;Farber,JayP;Foreman,RobertD
先前的研究表明，突触后背柱通路中的薄核在传递来自盆腔内脏器官的伤害性信息方面发挥着重要作用。本研究的目的是比较有害心脏刺激对大鼠楔状核和上胸脊髓神经元活动的影响。在戊巴比妥麻醉、通气和瘫痪的雄性大鼠中记录楔状核和上胸椎（T3）脊髓中单个神经元的细胞外电位。为了激活心脏伤害感受器，将硅胶管放入左心室上方的心包囊中，注入缓激肽溶液（10μg/ml，0.2ml，1分钟）。对心包内缓激肽有反应的楔形神经元数量（IB，15.6%，17/109）显着少于T3神经元（43.2%，48/111，P<0.05）。 IB 兴奋 9/17 (52.9%) 楔形神经元并抑制 8 个神经元。相比之下，IB 兴奋的脊髓反应神经元比例显着高于楔形核中的反应神经元 (43/48, 89.6%, P<0.01)。楔形神经元对IB的短潜伏期/长持续反应的比例（14/3）显着高于脊髓神经元的反应（26/22，P<0.05）。 IB激发的楔形神经元的自发活动（5.5±0.7 imp/s）、反应幅度（6.0±0.6 imp/s）和持续时间（83.4±10.8秒）均显着小于脊髓神经元（11.5±1.3 imp/s、20.4±2.0 imp/s和104.9±7.0 imp/s，P<0.01，分别为 P<0.01、P<0.05）。这些结果表明，与上胸椎神经元相比，楔形核神经元在心脏伤害性信息的传递中发挥相对较小的作用。
Previous studies have shown that the gracile nucleus in postsynaptic dorsal column pathway plays an important role in conveying nociceptive information from pelvic visceral organs. The purpose of this study was to compare effects of a noxious cardiac stimulus on neuronal activity in the cuneate nucleus and upper thoracic spinal cord in rats. Extracellular potentials of single neurons in the cuneate nucleus and upper thoracic (T3) spinal cord were recorded in pentobarbital anesthetized, ventilated and paralyzed male rats. To activate cardiac nociceptors, a silicone tube was placed in the pericardial sac over the left ventricle to administer a solution of bradykinin (10μg/ml, 0.2ml, 1min). The number of cuneate neurons responding to intrapericardial bradykinin (IB, 15.6%, 17/109) was significantly less than for T3 neurons (43.2%, 48/111, P<0.05). IB excited 9/17 (52.9%) cuneate neurons and inhibited eight neurons. In contrast, IB excited a significantly higher percentage of responding spinal neurons than those in cuneate nucleus (43/48, 89.6%, P<0.01). The ratio of short latency/long-lasting responses of cuneate neurons to IB (14/3) were significant higher than responses of spinal neurons (26/22, P<0.05). Spontaneous activity (5.5±0.7 imp/s), response amplitudes (6.0±0.6 imp/s) and durations (83.4±10.8sec) of cuneate neurons excited by IB were significantly less than for spinal neurons (11.5±1.3 imp/s, 20.4±2.0 imp/s and 104.9±7.0 imp/s, P<0.01, P<0.01, P<0.05), respectively. These results indicate that the cuneate nucleus neurons play a relatively minor role in transmission of cardiac nociceptive information in comparison to upper thoracic spinal neurons.