Membrane properties and monosynaptic retinal excitation of neurons in the turtle accessory optic system.
Membrane properties and monosynaptic retinal excitation of neurons in the turtle accessory optic system.
复制标题
乌龟辅助视神经系统神经元的膜特性和单突触视网膜兴奋。
DOI：
10.1152/jn.1997.78.2.614
复制
发表时间：
1997
影响因子：
2.5
通讯作者：
Ariel,M
中科院分区：
文献类型：
--
作者：
Kogo,N;Ariel,M
黄志文，等.海龟辅助视系统神经元的膜特性和单突触视网膜兴奋.神经生理学杂志，1997，第78卷，第614-627页.使用眼贴离体脑干制备的海龟，伪鼠scripta elegans，结合全细胞补丁技术，我们记录了细胞内活动的辅助视系统神经元的基底视核（BON）。这项技术提供了对单个突触事件的长期稳定记录。在减少准备（大部分背侧结构被删除），大的自发兴奋性突触输入[兴奋性突触后电位（EPSP）]经常被记录。自发抑制性突触后电位很少观察到，除了在少数情况下。大部分EPSP在利多卡因注入视网膜后消失。少数小尺寸的EPSP仍然存在，这表明这些EPSP可能来自颅内来源，或者可能是来自视网膜神经节细胞轴突终末的微型自发突触电位。电刺激对侧视神经同步诱发群体EPSP。他们的恒定的发病潜伏期和他们的能力，遵循短间隔配对刺激表明，人口EPSP的反应是单突触。视觉诱发的BON棘波和EPSP输入到BON显示方向敏感性时，一个移动的模式被投射到整个对侧视网膜。使用较小的移动模式，识别单个BON细胞的感受野。投射在感受野内的一个小光点引导双极刺激电极的放置，以激活视网膜神经节细胞，从而为该BON细胞提供输入。这种视网膜微刺激诱发的EPSP表现出单一EPSP的特征。这些EPSP具有明显的低电流阈值。其他输入的招募仅在刺激水平大幅增加至阈值以上时才明显。诱发的单一EPSP的平均大小为7.8 mV，证实了该系统相对于非突触噪声的突触输入的大尺寸。绘制EPSP形状（上升时间与振幅），使用诱发的单一EPSP或自发EPSP。与自发EPSP样本不同，来自许多单一EPSP的数据在这些散点图中形成了不同的簇，表明这些EPSP在整个EPSP群体中具有独特的形状。在大多数研究的BON细胞中，超极化激活通道引起缓慢的去极化下降，在0.5-1 s内达到平台。这一特性表明，BON细胞可能比方向敏感性视网膜神经节细胞会聚形成中央视网膜滑移信号以控制眼反射的简单位点更复杂。
Kogo, Naoki and Michael Ariel.Membrane properties and monosynaptic retinal excitation of neurons in the turtle accessory optic system.J. Neurophysiol.78: 614–627, 1997. Using an eye-attached isolated brain stem preparation of a turtle,Pseudemys scripta elegans,in conjunction with whole cell patch techniques, we recorded intracellular activity of accessory optic system neurons in the basal optic nucleus (BON). This technique offered long-lasting stable recordings of individual synaptic events. In the reduced preparation (most of the dorsal structures were removed), large spontaneous excitatory synaptic inputs [excitatory postsynaptic potentials (EPSPs)] were frequently recorded. Spontaneous inhibitory postsynaptic potentials were rarely observed except in few cases. Most EPSPs disappeared after injection of lidocaine into the retina. A few EPSPs of small size remained, suggesting that these EPSPs either were from intracranial sources or may have been miniature spontaneous synaptic potentials from retinal ganglion cell axon terminals. Population EPSPs were synchronously evoked by electrical stimulation of the contralateral optic nerve. Their constant onset latency and their ability to follow short-interval paired stimulation indicated that much of the population EPSP's response was monosynaptic. Visually evoked BON spikes and EPSP inputs to BON showed direction sensitivity when a moving pattern was projected onto the entire contralateral retina. With the use of smaller moving patterns, the receptive field of an individual BON cell was identified. A small spot of light, projected within the receptive field, guided the placement of a bipolar stimulation electrode to activate retinal ganglion cells that provided input to that BON cell. EPSPs evoked by this retinal microstimulation showed features of unitary EPSPs. Those EPSPs had distinct low current thresholds. Recruitment of other inputs was only evident when the stimulation level was increased substantially above threshold. The average size of evoked unitary EPSPs was 7.8 mV, confirming the large size of synaptic inputs of this system relative to nonsynaptic noise. EPSP shape was plotted (rise time vs. amplitude), with the use of either evoked unitary EPSPs or spontaneous EPSPs. Unlike samples of spontaneous EPSPs, data from many unitary EPSPs formed distinct clusters in these scatterplots, indicating that these EPSPs had a unique shape among the whole population of EPSPs. In most BON cells studied, hyperpolarization-activated channels caused a slow depolarization sag that reached a plateau within 0.5–1 s. This property suggests that BON cells may be more complicated than a simple site for convergence of direction-sensitive retinal ganglion cells to form a central retinal slip signal for control of oculomotor reflexes.