A possible synaptic configuration underlying coeruleospinal inhibition of visceral nociceptive transmission in the rat.
A possible synaptic configuration underlying coeruleospinal inhibition of visceral nociceptive transmission in the rat.
复制标题
蓝脊髓抑制大鼠内脏伤害性传递的可能的突触结构。
DOI：
10.1007/s10072-011-0739-5
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发表时间：
2012
期刊：
影响因子：
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通讯作者：
Inoue T.
中科院分区：
文献类型：
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作者：
Hayashi B;Tsuruoka M;Maeda M;Tamaki J;Inoue T.
在麻醉大鼠中研究了蓝斑/蓝斑下层（LC/SC）对脊髓内脏伤害性传递的下行抑制的突触排列。使用碳丝玻璃微电极 (4–6 MΩ) 从 L6-S2 节段水平进行细胞外记录。结直肠扩张（CRD）是通过在降结肠和直肠内充气气球而产生的。所有测试的神经元都对 CRD 和皮肤挤压（613 g/mm2 的力）做出反应，表明来自内脏器官的伤害性信号和来自皮肤感受野的伤害性信号汇聚到单个神经元上。这些神经元根据对 CRD 的反应分为两组：短潜伏期突发神经元和短潜伏期持续神经元。 LC/SC 的电刺激（30 或 50 μA、100 Hz、0.1 ms 脉冲）抑制短潜伏期突发和短潜伏期持续神经元中 CRD 诱发和皮肤捏捏诱发反应。当提供分级 CRD（20、40、60 和 80 mmHg）时，LC/SC 刺激会导致线性 CRD 强度-反应幅度曲线的斜率降低，而短潜伏期突变神经元 (n= 42) 和短潜伏期持续神经元 (n= 11) 的反应阈值没有变化。这一结果表明，蓝脊髓对内脏伤害性传递的抑制是由于突触结构所致，其中抑制性和兴奋性末梢在空间上非常接近，包括突触前抑制。
A synaptic arrangement underlying descending inhibition from the locus coeruleus/subcoeruleus (LC/SC) on visceral nociceptive transmission in the spinal cord was investigated in the anesthetized rat. Extracellular recordings were made from the L6-S2segmental level using a carbon filament glass microelectrode (4–6 MΩ). Colorectal distention (CRD) was produced by inflating a balloon inside the descending colon and rectum. All neurons tested responded to both CRD and to cutaneous pinch (a force of 613 g/mm2), indicating that nociceptive signals from visceral organs and nociceptive signals from the cutaneous receptive field converge on a single neuron. These neurons were divided into two groups based on their response to CRD: short latency-abrupt and short latency-sustained neurons. Electrical stimulation of the LC/SC (30 or 50 μA, 100 Hz, 0.1 ms pulses) inhibited both CRD-evoked and cutaneous pinch-evoked responses in short latency-abrupt and short latency-sustained neurons. When graded CRD (20, 40, 60, and 80 mmHg) was delivered, LC/SC stimulation produced a reduction in slope of the linear CRD intensity-response magnitude curve without a change in the response threshold in both short latency-abrupt (n= 42) and short latency-sustained neurons (n= 11). This result suggests that coeruleospinal inhibition of visceral nociceptive transmission is due to a synaptic configuration in which inhibitory and excitatory terminals are in close spatial proximity, including presynaptic inhibition.