中国神经再生研究(英文版) ›› 2017, Vol. 12 ›› Issue (7): 1079-1085.doi: 10.4103/1673-5374.211186

• 原著:神经损伤修复保护与再生 • 上一篇    下一篇

大脑皮质锥体神经元兴奋性调节与轴突抑制输入的双重作用

  

  • 收稿日期:2017-06-07 出版日期:2017-07-15 发布日期:2017-07-15
  • 基金资助:

    国家自然科学基金(31500836, 81671288); 安徽省自然科学基金(1608085QH176).

Dual face of axonal inhibitory inputs in the modulation of neuronal excitability in cortical pyramidal neurons

Lei Jiang1, 2, Hong Ni1, Qi-yi Wang3, Li Huang1, Shi-di Zhao1, Jian-dong Yu4, Rong-jing Ge1   

  1. 1 Department of Pathophysiology, Bengbu Medical College, Bengbu, Anhui Province, China; 2 Department of General Surgery, The Second Affiliated Hospital of Bengbu Medical College, Bengbu, Anhui Province, China; 3 Department of Physiology, Bengbu Medical College, Bengbu, Anhui Province, China; 4 Guangdong-Hongkong-Macau Institute of CNS Regeneration, Joint International Research Laboratory of CNS Regeneration, Ministry of Education, Jinan University, Guangzhou, Guangdong Province, China
  • Received:2017-06-07 Online:2017-07-15 Published:2017-07-15
  • Contact: Rong-jing Ge, M.D., Ph.D., cathy0471@163.com.
  • Supported by:

    This study was supported by the National Natural Science Foundation of China, No. 31500836, 81671288; the Natural Science Foundation
    of Anhui Province of China, No. 1608085QH176.

摘要:

受到轴突细微结构的限制,轴突上的抑制性电位如何调节神经元活动尚未在单个神经元上得到证实。为此,实验以小鼠大脑皮质锥体神经元胞体与轴突为观察对象,运用胞体轴突配对记录,同时记录胞体和轴突的电位变化,模拟轴突上抑制性输入对神经元兴奋性的调节作用。发现小鼠大脑皮质锥体神经元的阈下电位可从轴突稳定传导至胞体,与上游信息整合从而影响神经元兴奋性。轴突上抑制性电位对神经元活动的影响取决于轴突抑制性电位与上游信息在时相上的整合:若轴突上抑制性电位与胞体去极化同步发生,则削弱上游去极化幅度,抑制动作电位产生,降低神经元兴奋性;若轴突抑制性电位发生在神经元产生动作电位之后,则促进后续动作电位的产生,增加神经元动作电位的发放数量和发放精确性。结果证实轴突抑制输入在大脑皮质锥体神经元兴奋性调节中具有双重作用,轴突上的抑制输入对神经元活动发挥抑制还是易化作用,取决于神经元网络的连接模式。

ORCID:0000-0002-8633-7004(Rong-jing Ge)

关键词: 神经再生, 皮质, 锥体神经元, 胞体, 轴突, 超极化, 神经网络, 时相整合, 前馈抑制, 反馈抑制, 兴奋性

Abstract:

Limited by the tiny structure of axons, the effects of these axonal hyperpolarizing inputs on neuronal activity have not been directly elucidated. Here, we imitated these processes by simultaneously recording the activities of the somas and proximal axons of cortical pyramidal neurons. We found that spikes and subthreshold potentials propagate between somas and axons with high fidelity. Furthermore, inhibitory inputs on axons have opposite effects on neuronal activity according to their temporal integration with upstream signals. Concurrent with somatic depolarization, inhibitory inputs on axons decrease neuronal excitability and impede spike generation. In addition, following action potentials, inhibitory inputs on an axon increase neuronal spike capacity and improve spike precision. These results indicate that inhibitory inputs on proximal axons have dual regulatory functions in neuronal activity (suppression or facilitation) according to neuronal network patterns.

Key words: nerve regeneration, cortex, pyramidal neuron, soma, axon, hyperpolarization, neuronal network, feedforward inhibition, temporal integration, feedback inhibition, excitability, neural regeneration