对分离的海龟嗅球中二尖瓣细胞突触电位的分析。

Analysis of synaptic potentials in mitral cells in the isolated turtle olfactory bulb.

作者信息

Mori K, Nowycky M C, Shepherd G M

出版信息

J Physiol. 1981 May;314:295-309. doi: 10.1113/jphysiol.1981.sp013708.

DOI:10.1113/jphysiol.1981.sp013708

PMID:7310693

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC1249434/

Abstract

The synaptic responses of mitral cells have been analysed in intracellular recordings from the isolated olfactory bulb of the turtle. 2. The response of a mitral cell to a single volley in the lateral olfactory tract consisted of and antidromic impulse and a complex hyperpolarizing potential that had the properties of an inhibitory post-synaptic potential. The inhibitory response consisted of two successive components I1 and I2, followed by a prolonged hyperpolarization. 3. High-gain recordings revealed miniature hyperpolarizing potentials during the I1 and I2 responses. Both the miniature potentials and the I1 and I2 responses were increased in amplitude by depolarizing injected currents, and decreased and reversed in polarity by hyperpolarizing currents. The input conductance was increased during the I2 component. In some cells the I1 and I2 components, recorded with micropipettes filled with potassium acetate or potassium citrate, were depolarizing. 4 A single orthodromic volley in the olfactory nerves elicited a complex depolarizing-hyperpolarizing potential in mitral cells. The depolarization consisted of two successive components, E1 and E2. The hyperpolarization consisted of two successive components, I1 and I2, followed by a prolonged hyperpolarization. 5. The depolarizing components had the properties of excitatory post-synaptic potentials. They decreased in amplitude with depolarizing current injection and increased with hyperpolarizing injection. The hyperpolarizing components resembled the I1 and I2 components of the tract-evoked responses in their timing and properties. 6. It is postulated that the E1 component reflects the initial excitation by olfactory nerve terminals of the mitral cell dendritic tufts in the olfactory glomeruli. The I1 component is postulated to arise from dendrodendritic synaptic input mediated by interneurones, mainly granule cells. The E2 and I2 components are likely to arise mainly from intrinsic synaptic circuits within the olfactory bulb.

摘要

已在海龟离体嗅球的细胞内记录中分析了二尖瓣细胞的突触反应。2. 二尖瓣细胞对嗅外侧束单个冲动的反应包括一个逆行冲动和一个具有抑制性突触后电位特性的复合超极化电位。抑制性反应由两个连续的成分I1和I2组成，随后是一个延长的超极化。3. 高增益记录显示在I1和I2反应期间有微小超极化电位。微小电位以及I1和I2反应的幅度都因去极化注入电流而增加，因超极化电流而减小并极性反转。在I2成分期间输入电导增加。在一些细胞中，用充满醋酸钾或柠檬酸钾的微电极记录的I1和I2成分是去极化的。4. 嗅神经中的单个顺行冲动在二尖瓣细胞中引发一个复合的去极化 - 超极化电位。去极化由两个连续的成分E1和E2组成。超极化由两个连续的成分I1和I2组成，随后是一个延长的超极化。5. 去极化成分具有兴奋性突触后电位的特性。它们的幅度随着去极化电流注入而减小，随着超极化注入而增加。超极化成分在时间和特性上类似于束诱发反应的I1和I2成分。6. 据推测，E1成分反映了嗅球嗅小球中二尖瓣细胞树突簇的嗅神经末梢的初始兴奋。I1成分据推测源于主要由颗粒细胞介导的中间神经元的树 - 树突触输入。E2和I2成分可能主要源于嗅球内的内在突触回路。