Transmission mediated with and without spikes at connexions between large second-order neurones of locust ocelli
Transmission mediated with and without spikes at connexions between large second-order neurones of locust ocelli
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蝗虫单眼大二级神经元之间连接处有或没有尖峰介导的传输
DOI：
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发表时间：
1982
期刊：
影响因子：
--
通讯作者：
P. Simmons
中科院分区：
文献类型：
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作者：
P. Simmons
刺槐眼部大型二级神经元(L神经元)既有兴奋性联系，也有抑制性联系。小的、渐进式的去极化和超极化是在兴奋性连接处传递的，但在抑制性连接处，突触前神经元中的尖峰信号是传递所必需的。1.L-神经元在超极化迅速结束时，通常只有一次尖峰。超极化可能是由眼内照射引起的，也可能是由注入电流引起的。棘波的幅度取决于先前超极化的幅度和持续时间(图1B)。2.在兴奋性连接处，突触前神经元的静息电位通常从传递的阈值去极化，因此小的超极化和去极化都会影响突触后电位的变化(图2A，B)。在几分钟的时间内，这些连接处的传输没有减少的迹象(图2D)。突触前神经元的尖峰通常确保突触后神经元也出现尖峰。3.在抑制性连接中，突触后电位在10-20ms内下降(图3A)。正因为如此，快速上升的突触前电位，如棘波，需要进行传递。此外，突触前超极化不会影响突触后电位的变化。在抑制突触后电位之后，抑制连接的传递保持抑制约一秒钟(图3B，C)。4.外侧眼神经细胞的一个解剖类别的L神经元(L1-3；C.S.Goodman 1976)的所有三个成员彼此之间建立相互的抑制连接(图7B；表1)。其中一些神经元与另一类神经元在兴奋性连接时是突触前的(L4-5；图7A)。许多L神经元并不投射到整个视网膜区域，大多数投射到背侧或腹侧半部(图6)。兴奋性连接可以增强对光照减弱的反应，而抑制性连接可以增强对大对象快速运动的检测，例如视界。
SummaryLarge second-order neurones of locust ocelli (L-neurones) make both excitatory and inhibitory connexions with each other. Small, graded depolarisations and hyperpolarisations are transmitted at the excitatory connexions but, at the inhibitory connexions, spikes in the presynaptic neurone are required for transmission.1.L-neurones spike, usually once only, when hyperpolarisations end rapidly. The hyperpolarisations can be caused either by illumination of the ocellus, or by injection of current. The amplitude of a spike depends both upon the amplitude and the duration of the preceding hyperpolarisation (Fig. 1B).2.At the excitatory connexions, the resting potential of the presynaptic neurone normally lies depolarised from the threshold for transmission, so that both small hyperpolarisations and depolarisations effect changes in postsynaptic potential (Fig. 2A, B). Over periods of several minutes, there is no sign of decrement in transmission at these connexions (Fig. 2D). Spikes in the presynaptic neurone usually ensure that the postsynaptic neurone also spikes.3.At the inhibitory connexions, the postsynaptic potential decrements within 10–20 ms (Fig. 3A). Because of this, rapidly rising presynaptic potentials, such as spikes, are required for transmission. Also, presynaptic hyperpolarisations do not effect changes in postsynaptic potential. Following an inhibitory postsynaptic potential, transmission at an inhibitory connexion remains depressed for about a second (Figs. 3B, C).4.All three members of one anatomical class of L-neurone (L1–3; C.S. Goodman 1976) of a lateral ocellus make reciprocal inhibitory connexions with each other (Fig. 7B; Table 1). Some of these neurones are presynaptic at excitatory connexions with another class (L4–5; Fig. 7A). Many L-neurones do not project to the whole area of the retina, and most project to the dorsal or ventral halves (Fig. 6). The excitatory connexions may sharpen responsiveness to decreases in illumination, and the inhibitory connexions may enhance the detection of rapid movements of large objects, such as the visual horizon.
螃蟹的非冲动拉伸感受器复合体：强直感觉运动突触的去极化-释放耦合研究。
DOI：
10.1098/rstb.1980.0092
发表时间：
1980
期刊：
Proceedings of the Clinical Dialysis and Transplant Forum
影响因子：
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作者：
Blight,AR;Llinás,R
通讯作者：
Llinás,R