ELECTROPHYSIOLOGY OF CAUDAL NEUROSECRETORY CELLS IN THE SKATE AND FLUKE
ELECTROPHYSIOLOGY OF CAUDAL NEUROSECRETORY CELLS IN THE SKATE AND FLUKE
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DOI：
10.1016/0016-6480(62)90031-x
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发表时间：
1962-01-01
影响因子：
2.7
通讯作者：
FOX, S
中科院分区：
文献类型：
--
作者：
BENNETT, MVL;FOX, S
本文对两种鳐（Raja erinacea和R.本文应用细胞内微电极技术研究了中国对虾（Paralichthys dentatus）和中国对虾（Paralichthys dentatus）的细胞内微电极。这些细胞能够产生尖峰信号并被突触激活。神经分泌细胞的旱冰鞋是混杂在脊髓内的其他神经元，不能穿透视觉控制。然而，一类反应记录，很容易区分的运动神经元和有髓纤维，这很可能来自更大的神经分泌细胞。尖峰持续时间较长，并有明显的下冲。在脊髓表面附近刺激直接激活细胞体，而不是引起逆向尖峰。短暂的刺激，内部或外部，可以产生非常长的潜伏期的直接尖峰，从而表明低程度的调节。突触前通路传导速度慢，阈值高。神经分泌细胞的吸虫解剖分离从其他细胞体，但记录轴突和胞体有区别的电生理。从细胞体记录的特点是发生突触后电位，这可能是足够的启动尖峰。尖峰的持续时间相当长，通常会有一个下冲。对逆向刺激的反应在轴突丘的传播延迟引起的上升相上有拐点。索马的侵入可被超极化或不应性阻断，留下锋电位的轴突成分。轴突起始部分的阈值并不显著低于索马。对短暂的阈值刺激的反应的长潜伏期表明，几乎没有调节。当刺激在尿垂体上方时，细胞内的逆向反应往往有几个明显的潜伏期。较长的潜伏期反应的性质表明，它们是在轴突的终端发起的，并且延迟是由于在这些结构中非常缓慢的传播造成的。逆向传导可在轴突中距索马一定距离的点以及轴突丘处被阻断。从神经分泌轴突记录的尖峰的持续时间类似的细胞体。它们的特点是发生突触诱发的棘波没有记录的p.s.p.这足以激发它们或对记录部位两侧的刺激产生直接反应。超极化可导致沿轴突的传播沿着受阻，这与所记录的尖峰的稍后分量的受阻相关联。突触前通路向前延伸至神经分泌细胞。其传导速度提示其由细小的有髓纤维组成。个别突触前纤维似乎同时支配吻侧和尾侧细胞。静脉注射低渗溶液可以引起突触前纤维的足够活动，从而在神经分泌细胞中启动冲动。
The caudal neurosecretory cells of two species of skate (Raja erinacea and R. ocellata) and of the fluke (Paralichthys dentatus) were studied by intracellular microelectrode techniques. The cells were capable of producing spikes and of being synaptically activated. The neurosecretory cells of the skate were intermingled with other neurons within the spinal cord and could not be penetrated under visual control. However, a class of responses was recorded that were readily distinguishable from those of motoneurons and myelinated fibers and which very likely came from the much larger neurosecretory cells. The spikes were longer in duration and had pronounced undershoots. Nearby stimulation on the surface of the cord activated the cell bodies directly rather than evoking antidromic spikes. Brief stimuli, intra- or extracellular, could produce direct spikes of very long latency, thus indicating a low degree of accommodation. The presynaptic pathway was slowly conducting and of high threshold. The neurosecretory cells of the fluke were anatomically isolated from other cell bodies, but recordings from axons and somata had to be distinguished electrophysiologically. Recordings from cell bodies were characterized by the occurrence of postsynaptic potentials, which could be adequate to initiate spikes. The spikes were rather long in duration and usually followed by an undershoot. Those in response to antidromic stimulation had an inflection on the rising phase caused by delay of propagation at the axon hillock. Invasion of the soma could be blocked by hyperpolarization or refractoriness, leaving the axonal component of the spike. The threshold in the initial part of the axon was not significantly lower than in the soma. There was little accommodation, as indicated by the long latencies of responses to brief threshold stimuli. The antidromic responses in a cell often had several distinct latencies when stimulation was over the urohypophysis. The properties of the longer latency responses suggested that they were initiated in the terminals of the axons and that the delay resulted from very slow propagation in these structures. Antidromic conduction could be blocked in the axon at points some distance from the soma as well as at the axon hillock. Spikes recorded from the neurosecretory axons were similar in duration to those from the cell bodies. They were characterized by the occurrence either of synaptically evoked spikes without recording of p.s.p.''s adequate to iniate them or of direct responses to stimulation on each side of the recording site. Hyperpolarization could cause block of propagation along the axon which was associated with block of a later component of the recorded spike. The presynaptic pathway ran anteriorly to the neurosecretory cells. Its conduction velocity suggested that it consisted of small myelinated fibers. The individual presynaptic fibers appeared to innervate both rostral and caudal cells. Intravenous injections of hypotonic solutions could cause sufficient activity in the presynaptic fibers to initiate impulses in the neurosecretory cells.