...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>The Journal of Neuroscience: The Official Journal of the Society for Neuroscience >Ionic mechanisms underlying autonomous action potential generation in the somata and dendrites of GABAergic substantia nigra pars reticulata neurons in vitro.
【24h】

Ionic mechanisms underlying autonomous action potential generation in the somata and dendrites of GABAergic substantia nigra pars reticulata neurons in vitro.

机译：体外GABA能黑质实体神经元在体细胞和树突中自主动作电位产生的离子机制。

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Through their repetitive discharge, GABAergic neurons of the substantia nigra pars reticulata (SNr) tonically inhibit the target nuclei of the basal ganglia and the dopamine neurons of the midbrain. As the repetitive firing of SNr neurons persists in vitro, perforated, whole-cell and cell-attached patch-clamp recordings were made from rat brain slices to determine the mechanisms underlying this activity. The spontaneous activity of SNr neurons was not perturbed by the blockade of fast synaptic transmission, demonstrating that it was autonomous in nature. A subthreshold, slowly inactivating, voltage-dependent, tetrodotoxin (TTX)-sensitive Na+ current and a TTX-insensitive inward current that was mediated in part by Na+ were responsible for depolarization to action potential (AP) threshold. An apamin-sensitive spike afterhyperpolarization mediated by small-conductance Ca2+-dependent K+ (SK) channels was critical for the precision of autonomous activity. SK channels were activated, in part, by Ca(2+) flowing throughomega-conotoxin GVIA-sensitive, class 2.2 voltage-dependent Ca2+ channels. Although Cs+/ZD7288 (4-ethylphenylamino-1,2-dimethyl-6-methylaminopyrimidinium chloride)-sensitive hyperpolarization-activated currents were also observed in SNr neurons, they were activated at voltages that were in general more hyperpolarized than those associated with autonomous activity. Simultaneous somatic and dendritic recordings revealed that autonomously generated APs were observed first at the soma before propagating into dendrites up to 120 microm from the somatic recording site. Backpropagation of autonomously generated APs was reliable with no observable incidence of failure. Together, these data suggest that the resting inhibitory output of the basal ganglia relies, in large part, on the intrinsic firing properties of the neurons that convey this signal.
机译：通过反复放电，黑质网状组织（SNr）的GABA能神经元在声调上抑制基底神经节的靶核和中脑的多巴胺神经元。由于SNr神经元的重复发射在体外持续存在，因此从大鼠脑切片上进行了穿孔的全细胞和细胞附着的膜片钳记录，以确定该活性的基础。 SNr神经元的自发活动不受快速突触传递的阻碍，表明它是自然自治的。亚阈值，缓慢失活，依赖电压的河豚毒素（TTX）敏感的Na +电流和部分由Na +介导的TTX敏感的内向电流导致去极化至动作电位（AP）阈值。由小电导的依赖Ca2 +的K +（SK）通道介导的超极化后的一种对apapa敏感的峰值对于自主活动的精度至关重要。 SK通道部分地被流过ω-芋螺毒素GVIA敏感的2.2类电压依赖性Ca2 +通道激活的Ca（2+）激活。尽管在SNr神经元中也观察到Cs + / ZD7288（4-乙基苯基氨基-1,2-二甲基-6-甲基氨基嘧啶氯化物）敏感的超极化激活电流，但它们的激活电压通常比与自主活动相关的电压更超极化。体细胞和树突状细胞的同步记录显示，首先在体细胞中观察到自主产生的AP，然后传播到距体细胞记录部位最远120微米的树突中。自主生成的AP的反向传播是可靠的，没有可观察到的故障发生率。总之，这些数据表明，基底神经节的静息抑制输出在很大程度上取决于传递该信号的神经元的内在放电特性。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号