Lamina-specific membrane and discharge properties of rat spinal dorsal horn neurones in vitro
Lamina-specific membrane and discharge properties of rat spinal dorsal horn neurones in vitro
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DOI：
10.1113/jphysiol.2002.017756
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发表时间：
2002-05-15
影响因子：
5.5
通讯作者：
Sandkühler, J
中科院分区：
文献类型：
--
作者：
Ruscheweyh, R;Sandkühler, J
膜和放电特性决定了神经元的输入输出关系，因此对神经回路的功能至关重要。在这里，我们已经测试的假设，在不同的板层的脊髓背角的神经元在其电生理特性不同。采用全细胞膜片钳技术记录大鼠脊髓横切片背角神经元的主动和被动膜特性。背角浅层神经元比背角深层神经元具有更高的膜电阻和更宽的动作电位。动作电位阈值最高的椎板II神经元，代表低膜兴奋性。五种类型的射击模式被确定在响应去极化电流注入。紧张性放电神经元在整个电流脉冲中以固定的间隔释放动作电位。延迟放电的神经元表现出延迟的放电开始响应电流注射，这是由于激活的瞬态电压依赖性外向电流，大概是一个A电流。另一组神经元发出短暂的动作电位。单脉冲神经元在去极化脉冲开始时只释放一个动作电位。相爆发神经元表现出不规则的动作电位爆发。燃烧模式是不均匀分布在层。强直性放电神经元在板层I和更深的板层，但没有发现在板层II延迟放电神经元中遇到的板层I和II，但没有在更深的板层。大多数的神经元表现出最初的爆发被发现在板层II。这些膜和放电特性的差异可能有助于板层特异性处理感觉，包括伤害性，信息。
Membrane and discharge properties determine the input-output relationship of neurones and are therefore of paramount importance for the functions of neural circuits. Here, we have tested the hypothesis that neurones in different laminae of the spinal dorsal horn differ in their electro-physiological properties. Whole-cell patch-clamp recordings from dorsal horn neurones in a rat transverse spinal cord slice preparation were used to record active and passive membrane properties. Neurones from superficial dorsal horn laminae had higher membrane resistances and broader action potentials than deep dorsal horn neurones. Action potential thresholds were highest in lamina II neurones, representing low membrane excitability. Five types of firing patterns were identified in response to depolarising current injections. Tonic-firing neurones discharged action potentials at regular intervals throughout the current pulse. Delayed-firing neurones showed a delayed onset of firing in response to current injections that was due to activation of a transient voltage-dependent outward current, presumably an A-current. Another group of neurones fired a short initial burst of action potentials. Single-spiking neurones discharged only one action potential at the onset of a depolarising pulse. Phasic-bursting neurones showed irregular bursts of action potentials. Firing patterns were unequally distributed among laminae. Tonic-firing neurones were numerous in lamina I and deeper laminae but were not found in lamina II Delayed-firing neurones were encountered in laminae I and II but not in deeper laminae. Most of the neurones showing an initial burst were found in lamina II. These differences in membrane and discharge properties probably contribute to lamina-specific processing of sensory, including nociceptive, information.