Cellular properties of lateral spinal nucleus neurons in the rat L6-S1 spinal cord
Cellular properties of lateral spinal nucleus neurons in the rat L6-S1 spinal cord
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DOI：
10.1152/jn.1999.81.6.3078
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发表时间：
1999-06-01
影响因子：
2.5
通讯作者：
Gebhart, GF
中科院分区：
文献类型：
--
作者：
Jiang, MC;Liu, L;Gebhart, GF
在10 ~ 15日龄大鼠L 6-S1脊髓切片上，对26个脊髓外侧核（LSN）神经元进行了常规细胞内记录。在休息时，LSN神经元不发射自发动作电位。随着正电流脉冲的注入，动作电位的振幅为72 +/- 7（SD）mV，半峰高度的持续时间为0.75 +/- 0.22 ms。动作电位之后是后电位。大多数的LSN神经元（13/17）只表现出后超极化（AHP），四个神经元表现出快速和缓慢的AHP分离的后去极化（ADP）。对于仅表现出AHP的LSN神经元，可以在浴中应用蜂毒肽（100 mM）期间确定缓慢的ADP。11个LSN神经元中有4个出现抑制后反弹（PIR）。PIR有两种类型，一种为高阈值低振幅，另一种为低阈值高振幅。在0 mM Ca ~（2+）/高Mg ~（2+）（10 mM）记录溶液中，高振幅的PIR被部分阻断。在17个LSN神经元中检测重复放电特性。根据初始瞬时放电频率与稳态放电频率之间斜率的比值，识别出具有低发放频率适应的神经元（8/17）和具有高发放频率适应的神经元（4/17）。此外，2/17个LSN神经元表现出双相重复放电模式，由快速SFA、延迟兴奋和低SFA组成;另外2个神经元仅表现出延迟兴奋。在两个LSN神经元中也发现了平台电位。背根刺激显示，大多数的LSN神经元（12/13）的多突触后电位（PSP），只有一个神经元表现出单突触的PSP。电刺激背根诱发低SFA神经元的长时间放电和高SFA神经元的短放电。通过浴中应用P物质（SP）来调制固有特性。在所有8个测试的LSN神经元中，膜电位被去极化，并且膜电阻增加（n = 3）或降低（n = 2）。SP促进了瞬时放电和稳态放电。此外，在三个LSN神经元中诱导了膜电位振荡。这些结果表明，LSN神经元表现出多种内在特性，这可能显着有助于感觉加工，包括伤害性加工。
Conventional intracellular recordings were made from 26 lateral spinal nucleus (LSN) neurons in slices of L-6-S-1 spinal cord from 10- to 15-day-old rats. At rest, LSN neurons did not fire spontaneous action potentials. With injection of a positive current pulse, action potentials had an amplitude of 72 +/- 7 (SD) mV and duration at half-peak height of 0.75 +/- 0.22 ms. Action potentials were followed by an afterpotential. Most LSN neurons (13/17) exhibited only an afterhyperpolarization (AHP); four neurons exhibited both a fast and a slow AHP separated by an afterdepolarization (ADP). For LSN neurons that exhibited only an AHP, a slow ADP could be identified during bath application of apamin (100 mM). Four of 11 LSN neurons show ed a postinhibitory rebound (PIR). Two types of PIR were noted, one with high threshold and low amplitude and the other with low threshold and high amplitude. The PIR with high amplitude was partially blocked in 0 mM Ca2+/high Mg2+ (10 mM) recording solution. Repetitive firing properties were examined in 17 LSN neurons. On the basis of the ratio of the slopes between initial instantaneous firing and steady-state firing frequencies, neurons with low spike frequency adaptation (SFA, 8/17) and high SFA (4/17) were identified. In addition, 2/17 LSN neurons exhibited biphasic repetitive firing patterns, which were composed of a fast SFA, delayed excitation, and low SFA; another two neurons showed only delayed excitation. Plateau potentials also were found in two LSN neurons. Dorsal root stimulation revealed that most LSN neurons (12/13) had polysynaptic postsynaptic potentials (PSP); only one neuron exhibited a monosynaptic PSP. Electrical stimulation of the dorsal root evoked prolonged discharges in low SFA neurons and a short discharge in high SFA neurons. Intrinsic properties were modulated by bath application of substance P (SP). Membrane potentials were depolarized in all eight LSN neurons tested, and membrane resistance was either increased (n = 3) or decreased (n = 2). Both instantaneous firing and steady-state firing were facilitated by SP. In addition, oscillation of membrane potentials were induced in three LSN neurons. These results demonstrate that LSN neurons exhibit a variety of intrinsic properties, which may significantly contribute to sensory processing, including nociceptive processing.