PROPERTIES OF SOMATA OF SPINAL DORSAL-ROOT GANGLION-CELLS DIFFER ACCORDING TO PERIPHERAL RECEPTOR INNERVATED
PROPERTIES OF SOMATA OF SPINAL DORSAL-ROOT GANGLION-CELLS DIFFER ACCORDING TO PERIPHERAL RECEPTOR INNERVATED
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DOI：
10.1152/jn.1988.60.5.1584
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发表时间：
1988-11-01
影响因子：
2.5
通讯作者：
MENDELL, LM
中科院分区：
文献类型：
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作者：
KOERBER, HR;DRUZINSKY, RE;MENDELL, LM
1. 在用 α-氯醛糖麻醉的猫的 L7 或 S1 DRG 中的背根神经节细胞体中进行细胞内记录。测量动作电位的特性（幅度、持续时间、峰值上升率）、后超极化（AHP）持续时间、内向整流幅度和轴突传导速度。确定了适当的刺激，并研究了这些特性的相关程度。 2.所有具有感受野的细胞都可以归类为机械感受器。大多数具有 A-β 轴突（大于 36 m/s）的细胞可以通过温和的机械刺激激活，但少数传导速度处于 A-β 范围低端的细胞是伤害感受器。具有 A-delta 轴突 (2-36 m/s) 的细胞支配非常敏感的唐毛囊 (D-hairs) 或高阈值机械感受器 (HTMR)。此外，还发现了一组无法描述其感受野的 A-delta 纤维。它们的尖峰、AHP 和膜特性与提供 HTMR 的细胞没有区别（见下文），并且它们与 A-delta-HTMR 集中在一起。 3. A-β-神经元比 A-δ-神经元表现出更小、更短的尖峰，即使是那些提供 D 毛的神经元也是如此。 A-β 细胞的峰值上升率 (dV/dt)max 和向内整流明显大于 A-delta 细胞，而 AHP 持续时间和输入电阻较小。然而，给定传导速度范围的细胞中这些参数的值通常与受体类型相关。 4.与D-毛发相比，A-delta-HTMR表现出更大的振幅和持续时间、更长的AHP持续时间和更小的内向整流。这些尖峰持续时间较长主要是由于其下降肢上有一个突出的驼峰。两组电池的输入电阻相似。 5. A-β-HTMR 与支配低阈值受体的 A-β 细胞不同，就像 A-delta-HTMR 与 D-毛发不同一样。然而，提供不同受体类型（例如，缓慢适应I型、Pacinian小体等）的A-β-LTMR在受体类型和体体的电生理学之间没有表现出相关性。 6. 尖峰参数的这些差异发生在膜水平，而不是在细胞侵入程度，因为最大幅值尖峰也表现出最慢的时间过程（即在 HTMR 中）。 AHP 持续时间和内向整流的系统变化也表明这些细胞中离子通道类型比例的差异。（摘要截断为 400 字）
1. Intracellular recordings were made in the somata of dorsal root ganglion cells in the L7 or S1 DRG in cats anesthetized with alpha-chloralose. The properties of the action potentials (amplitude, duration, peak rate of rise), duration of afterhyperpolarization (AHP), magnitude of inward rectification, and axonal conduction velocity were measured. The adequate stimulus was determined, and the extent to which these properties are correlated was investigated. 2. All cells with receptive fields could be classified as mechanoreceptors. Most cells with A-beta-axons (greater than 36 m/s) could be activated by gentle mechanical stimulation but a small minority with conduction velocity in the low end of the A-beta-range were nociceptors. Cells with A-delta-axons (2-36 m/s) innervated either the very sensitive Down hair follicles (D-hairs) or high-threshold mechanoreceptors (HTMRs). In addition a group of A-delta-fibers was found for which no receptive field could be described. Their spikes, AHPs, and membrane properties were indistinguishable from those of cells supplying HTMRs (see below) and they were lumped together with A-delta-HTMRs. 3. A-beta-neurons exhibited smaller, briefer spikes than A-delta-neurons, even those supplying D-hairs. Peak rate of rise (dV/dt)max and inward rectification were significantly larger in A-beta-cells than in A-delta s, whereas AHP duration and input resistance were smaller. However, the values of these parameters in cells of a given conduction velocity range were generally associated with receptor type. 4. A-delta-HTMRs exhibited spikes of greater amplitude and duration, longer AHP duration, and smaller inward rectification than D-hairs. The long duration of these spikes was due largely to a prominent hump on their descending limb. Input resistance was similar in both groups of cells. 5. A-beta-HTMRs differed from A-beta-cells innervating low threshold receptors in the same general way that A-delta-HTMRs differed from D-hairs. However, A-beta-LTMRs supplying different receptor types (e.g., slowly adapting type I, Pacinian corpuscles, etc.) exhibited no correlation between receptor type and electrophysiology of the soma. 6. These differences in spike parameters occur at the level of the membrane rather than in the degree of somal invasion because the largest amplitude spikes also exhibited the slowest time course (i.e., in HTMRs). Systematic variation in AHP duration and inward rectification also suggest differences in the proportions of ionic channel types among these cells.(ABSTRACT TRUNCATED AT 400 WORDS)