RESPONSES OF MITRAL CELLS TO STIMULATION OF LATERAL OLFACTORY TRACT IN RABBIT
RESPONSES OF MITRAL CELLS TO STIMULATION OF LATERAL OLFACTORY TRACT IN RABBIT
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DOI：
10.1113/jphysiol.1963.sp007178
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发表时间：
1963-01-01
影响因子：
5.5
通讯作者：
POWELL, TPS
中科院分区：
文献类型：
--
作者：
PHILLIPS, CG;SHEPHERD, GM;POWELL, TPS
在麻醉的兔子中，通过侧嗅束齐射在嗅球中引起的电位波与记录微电极尖端相对于球的组织学薄片的位置之间获得了相关性。嗅球中的二尖瓣细胞已通过其对外侧嗅束冲击的逆向反应以及这些反应位于二尖瓣细胞体层或附近的定位来识别。在细胞外微量移液器的记录中经常获得高达 73 mV 峰峰值电位的“巨大”尖峰。对侧嗅束的配对和重复电击表明，逆向冲动侵入二尖瓣细胞中可兴奋膜的连续区域。在这种生理特性中，二尖瓣细胞类似于脊髓运动神经元和中枢神经系统的其他神经元，尽管它们的形态不同。条件侧嗅束齐射太弱，无法激发采样的二尖瓣细胞的轴突，通常会在阈上测试电击后产生长期的逆向入侵阻塞。细胞内记录表明，阻塞与二尖瓣细胞膜上的抑制性突触后电位有关。通过与运动神经元和“皮质”锥体细胞类比，表明这种阻塞是由二尖瓣轴突的循环侧枝激活的球内神经元系统介导的。不能排除在侧嗅束中运行的离心纤维是实验中一个复杂因素的可能性。
In anaesthetized rabbits a correlation has been obtained between the potential waves evoked in the olfactory bulb by lateral olfactory tract volleys and the position of the tip of a recording micro-electrode in relation to the histological laminae of the bulb. Mitral cells in the olfactory bulb have been identified by their antidromic responses to shocks to the lateral olfactory tract, and by the localization of these responses at or near to the layer of mitral cell bodies. "Giant" spikes, of up to 73 mV peak-to-peak potential, have been regularly obtained in recordings with extracellular micropipettes. Paired and repetitive shocks to the lateral olfactory tract have shown that an antidromic impulse invades successive regions of excitable membrane in the mitral cell. In this physiological property the mitral cells resemble spinal motoneurones and other neurones of the central nervous system, in spite of their different morphology. Conditioning lateral olfactory tract volleys, too weak to excite the axon of a sampled mitral cell, often produce a long-lasting blockage of antidromic invasion following suprathreshold testing shocks. Intracellular recordings indicate that blockage is associated with an inhibitory post-synaptic potential across the mitral cell membrane. By analogy with motoneurones and "cortical" pyramidal cells, it is suggested that this blockage is mediated by intra-bulbar neuronal systems activated by recurrent collaterals of the mitral axons. The possibility that centrifugal fibres running in the lateral olfactory tract were a complicating factor in the experiments could not be excluded.