Two distinct types of inhibition mediated by cartwheel cells in the dorsal cochlear nucleus.
Two distinct types of inhibition mediated by cartwheel cells in the dorsal cochlear nucleus.
复制标题
耳蜗背核中的侧手翻细胞介导的两种不同类型的抑制。
DOI：
10.1152/jn.91272.2008
复制
发表时间：
2009
影响因子：
2.5
通讯作者：
Manis,PaulB
中科院分区：
文献类型：
--
作者：
Mancilla,JaimeG;Manis,PaulB
个别神经元已被证明在几个脑区中表现出靶细胞特异性突触功能。突触后电导的时程对局部神经网络的动力学行为有着重要的影响。车轮细胞（CWC）是耳蜗背核（DCN）中数量最多的抑制性中间神经元。它们由携带多感觉信息的平行纤维突触兴奋，并反过来抑制其他CWC和DCN的主要投射神经元，锥体细胞（PC）。CWC与"上下文依赖性"抑制有关，产生去极化（其他CWC）或超极化（PC）突触后电位。在本研究中，我们使用成对的全细胞记录来检查新生大鼠DCN切片中CWC的靶依赖性抑制。我们发现，CWC抑制性突触后电位（IPSP）到PC是大（1.3 mV）和短暂（半宽度= 11.8 ms），而CWC IPSP到其他CWC是小（0.2 mV）和缓慢（半宽度= 36.8 ms）。CWC之间的诱发IPSP表现出成对脉冲易化，而CWC到PC上的IPSP表现出成对脉冲抑制。穿孔斑片记录显示，CWC中的自发IPSP在静息时是超极化的，平均估计逆转电位为− 67 mV。自发IPSC在CWC中比在PC中更小且持续时间更长，这表明受体的动力学在两种细胞类型中是不同的。这些结果表明，CWC在DCN中起着双重作用。CWC-CWC网络的相互作用是缓慢的，敏感的平均速率的CWC点火，而CWC-PC网络是快速的，敏感的瞬态变化的CWC点火。
Individual neurons have been shown to exhibit target cell-specific synaptic function in several brain areas. The time course of the postsynaptic conductances (PSCs) strongly influences the dynamics of local neural networks. Cartwheel cells (CWCs) are the most numerous inhibitory interneurons in the dorsal cochlear nucleus (DCN). They are excited by parallel fiber synapses, which carry polysensory information, and in turn inhibit other CWCs and the main projection neurons of the DCN, pyramidal cells (PCs). CWCs have been implicated in “context-dependent” inhibition, producing either depolarizing (other CWCs) or hyperpolarizing (PCs) post synaptic potentials. In the present study, we used paired whole cell recordings to examine target-dependent inhibition from CWCs in neonatal rat DCN slices. We found that CWC inhibitory postsynaptic potentials (IPSPs) onto PCs are large (1.3 mV) and brief (half-width = 11.8 ms), whereas CWC IPSPs onto other CWCs are small (0.2 mV) and slow (half-width = 36.8 ms). Evoked IPSPs between CWCs exhibit paired-pulse facilitation, while CWC IPSPs onto PCs exhibit paired-pulse depression. Perforated-patch recordings showed that spontaneous IPSPs in CWCs are hyperpolarizing at rest with a mean estimated reversal potential of −67 mV. Spontaneous IPSCs were smaller and lasted longer in CWCs than in PCs, suggesting that the kinetics of the receptors are different in the two cell types. These results reveal that CWCs play a dual role in the DCN. The CWC-CWC network interactions are slow and sensitive to the average rate of CWC firing, whereas the CWC-PC network is fast and sensitive to transient changes in CWC firing.