Comparison of the morphological and electrotonic properties of renshaw cells, ia inhibitory interneurons, and motoneurons in the cat
Comparison of the morphological and electrotonic properties of renshaw cells, ia inhibitory interneurons, and motoneurons in the cat
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DOI：
10.1152/jn.00533.2003
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发表时间：
2003-11-01
影响因子：
2.5
通讯作者：
Rose, PK
中科院分区：
文献类型：
--
作者：
Bui, TV;Cushing, S;Rose, PK
比较了4个运动神经元、8个Ia抑制性中间神经元和4个Renshaw细胞的形态学和电紧张特性。基于细胞三维重建的形态学分析显示，运动神经元的树突更长，分支更广泛。伦肖细胞的树突更短，结构更简单。Ia抑制性中间神经元的树突与运动神经元的树突一样长，分支结构与Renshaw细胞相似。室室模型用于确定从每个树突末端到体细胞的路径的电紧张特性。运动神经元稳态电压变化的衰减分别是Ia抑制性中间神经元和Renshaw细胞的3倍和7倍。电流衰减和电紧张长度的相对顺序相同。Renshaw细胞的树突输入阻抗分别是Ia抑制性中间神经元和运动神经元的2倍和4倍。这些电紧张特性的差异在高突触活动期间增加，正如R-m的减少所模拟的那样。短暂的突触样电导变化位点的电压瞬态峰值振幅高度依赖于细胞类别，Renshaw细胞最大，运动神经元最小。再加上瞬态电压信号衰减的类别差异，这导致了体细胞电压瞬态峰值幅度的巨大差异。电压瞬变的上升时间和半宽度也有不同。因此，基于被动属性，每个单元格类都有一组唯一的输入/输出属性。
The morphological and electrotonic properties of 4 motoneurons, 8 Ia inhibitory interneurons, and 4 Renshaw cells were compared. The morphological analysis, based on 3-D reconstructions of the cells, revealed that dendrites of motoneurons are longer and more extensively branched. Renshaw cells have dendrites that are shorter and simpler in structure. Dendrites of Ia inhibitory interneurons could be as long as those of motoneurons but the branching structure resembled that of Renshaw cells. Compartmental models were used to determine the electrotonic properties of the paths from each dendritic terminal to the soma. The attenuations of steady-state voltage changes in motoneurons were 3 and 7 times larger than in Ia inhibitory interneurons and Renshaw cells, respectively. The same relative order was observed for current attenuation and electrotonic length. The dendritic input resistances in Renshaw cells were 2 and 4 times larger than in Ia inhibitory interneurons and motoneurons, respectively. The difference in these electrotonic properties increased during higher synaptic activity as modeled by a decrease of R-m. The peak amplitudes of voltage transients at sites of brief, synaptic-like changes in conductance were highly dependent on cell class and were largest in Renshaw cells and smallest in motoneurons. In combination with class-specific differences in the attenuation of transient voltage signals, this led to large differences in the peak amplitudes of somatic voltage transients. Differences in the rise times and half-widths of the voltage transients were observed as well. Thus, based on passive properties, each cell class has a unique set of input/output properties.