Oertel D, Shatadal S, Cao X-J
Department of Physiology, University of Wisconsin School of Medicine and Public Health, 1300 University Avenue, Madison, WI 53706, USA.
Neuroscience. 2008 Jun 12;154(1):77-86. doi: 10.1016/j.neuroscience.2008.01.085. Epub 2008 Feb 29.
Principal cells of the ventral cochlear nucleus (VCN) differ in the magnitudes of low-voltage-activated potassium (gKL) and hyperpolarization-activated (gh) conductances that determine the time course of signaling. Octopus cells in mice have large gKL (500 nS) and gh (150 nS), bushy cells have smaller gKL (80 nS) and gh (30 nS), and T stellate cells have little gKL and a small gh (20 nS). gKL Arises through potassium channels of which approximately 60% contain Kv1.1 (potassium channels in the shaker or KCNA family) subunits; gh arises through channels that include hyperpolarization and cyclic nucleotide gated (HCN) 1 subunits. The surfaces of cell bodies and dendrites of octopus cells in the dorsocaudal pole, and of similar cells along the ventrolateral edge of the PVCN, were brightly labeled by an antibody against HCN1 that was colocalized with labeling for Kv1.1. More anteriorly neurons with little surface labeling were intermingled among cell bodies and dendrites with surface labeling for both proteins, likely corresponding to T stellate and bushy cells. The membrane-associated labeling patterns for Kv1.1 and HCN1 were consistent with what is known about the distribution and the electrophysiological properties of the principal cells of the VCN. The cytoplasm of large cells and axonal paranodes contained immunofluorescent labeling for only Kv1.1.
腹侧耳蜗核(VCN)的主细胞在决定信号传导时间进程的低电压激活钾(gKL)和超极化激活(gh)电导大小上存在差异。小鼠的章鱼细胞具有较大的gKL(500 nS)和gh(150 nS),毛细胞具有较小的gKL(80 nS)和gh(30 nS),而T星状细胞的gKL很小且gh也很小(20 nS)。gKL通过钾通道产生,其中约60%包含Kv1.1(震颤器或KCNA家族中的钾通道)亚基;gh通过包括超极化和环核苷酸门控(HCN)1亚基的通道产生。背尾极章鱼细胞以及PVCN腹外侧边缘类似细胞的胞体和树突表面,被抗HCN1抗体强烈标记,该抗体与Kv1.1的标记共定位。在更靠前的位置,表面标记很少的神经元与两种蛋白都有表面标记的胞体和树突混合在一起,可能对应于T星状细胞和毛细胞。Kv1.1和HCN1的膜相关标记模式与已知的VCN主细胞分布和电生理特性一致。大细胞的细胞质和轴突旁结仅含有Kv1.1的免疫荧光标记。