MODULATION OF ACTIVITY IN DORSAL-ROOT GANGLION NEURONS BY SYMPATHETIC ACTIVATION IN NERVE-INJURED RATS
MODULATION OF ACTIVITY IN DORSAL-ROOT GANGLION NEURONS BY SYMPATHETIC ACTIVATION IN NERVE-INJURED RATS
复制标题
DOI：
10.1152/jn.1994.71.1.38
复制
发表时间：
1994-01-01
影响因子：
2.5
通讯作者：
MICHAELIS, M
中科院分区：
文献类型：
--
作者：
DEVOR, M;JANIG, W;MICHAELIS, M
1.在大鼠坐骨神经切断后4-22天，对背根神经节（DRG）神经元的轴突进行了撕裂纤维记录。许多神经元有自发性异位放电起源于DRG内。2.当通过强直刺激T-13和L（1）前根（VR）激活终止于DRG的节后交感传出时，在超过一半的DRG神经元中，持续的传入放电发生了改变。在大多数的反应单位（62%），活动增加了这种交感神经刺激，在其余的（38%），活动受到抑制。单脉冲刺激交感传出神经没有影响。3.对交感神经刺激的反应在相当长的延迟（平均14.3 s）后开始，在10-20 s后达到峰值，然后在额外的20-30 s内恢复到基线。4.对交感神经刺激的兴奋性和抑制性反应，以及对全身应用肾上腺素的相应反应，均被α-肾上腺素受体拮抗剂酚妥拉明阻断。5.大多数对交感神经刺激有反应的活动DRG神经元，以及其他没有反应的神经元，都被共享同一DRG的相邻传入神经元的强直刺激所兴奋。这些“交叉放电后”反应不被酚妥拉明阻断。单脉冲刺激邻近的传入没有影响。6.神经损伤动物背根神经节中的交感神经感觉耦合为交感神经参与神经病性感觉功能障碍提供了一种以前未被怀疑的底物。
1. Teased-fiber recordings were made from the axons of dorsal root ganglion (DRG) neurons in rats that underwent transection of the sciatic nerve 4-22 days previously. Many of the neurons had spontaneous ectopic discharge originating from within the DRG. 2. When postganglionic sympathetic efferents ending in the DRG were activated by tetanic stimulation of the T-13 and L(1) ventral roots (VRs), the ongoing afferent discharge was altered in more than one-half of the DRG neurons sampled. In most of the responsive units (62%), activity was augmented by this sympathetic stimulation; in the remainder (38%), activity was suppressed. Single-pulse stimuli of sympathetic efferents had no effect. 3. Responses to sympathetic stimulation began after a substantial delay(mean 14.3 s), peaked after 10-20 s, and then returned toward baseline over an additional 20-30 s. 4. Both excitatory and suppressive responses to sympathetic stimulation, as well as corresponding responses to systemically applied adrenaline, were blocked by the alpha-adrenoreceptor antagonist phentolamine. 5. Most of the active DRG neurons that responded to sympathetic stimulation, as well as others that did not, were excited by tetanic stimulation of neighboring afferent neurons that share the same DRG. These ''crossed afterdischarge'' responses were not blocked by phentolamine. Single-pulse stimuli of neighboring afferents had no effect. 6. Sympathetic-sensory coupling in DRGs of nerve-injured animals provides a previously unsuspected substrate for sympathetic involvement in neuropathic sensory dysfunction.