Histamine: putative transmitter for lateral inhibition in Limulus eye.
Histamine: putative transmitter for lateral inhibition in Limulus eye.
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组胺：鲎眼中横向抑制的推定递质。
DOI：
10.1086/bblv193n2p203
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发表时间：
1997
期刊：
影响因子：
--
通讯作者：
Barlow,RB
中科院分区：
文献类型：
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作者：
Stewart,KM;Porcello,DM;McSweeney,ME;Saito,T;Passaglia,CL;Dodge,FA;Barlow,RB
侧抑制是许多神经系统中发现的整合机制。在视网膜中，它增强了视野中的边界和边缘（1）。自从H. Keffer Hartline和同事在1952年（2），侧抑制已被广泛研究（3）。它现在是视网膜功能综合模型的基础（4）。然而，有一个问题仍然没有答案。在鲎眼中，是什么神经递质介导了侧抑制？组胺被认为是节肢动物的两个主要类群（Uniramia和Crustacea）的感光神经递质（5、6、7）。在研究组胺的突触后效应的制剂中，组胺已被证明具有抑制作用（7，8）。生物化学研究表明，组胺和合成组胺的酶存在于鲎视网膜中（9），但没有生理学证据表明组胺是侧抑制的递质。在本文中，我们报告的电生理学和药理学研究，测试组胺在侧抑制的作用，在Limuluseye.In第一个实验中，我们测试组胺是否模仿的作用，侧抑制视神经活动产生的偏心细胞在个人小眼。为了获得偏心细胞，我们切除侧眼并将其切成三或四片。将一个切片置于Lucite灌注室（体积0.5ml）中。将填充有3 h4 KCl（25 MR）的玻璃微电极连接到DC桥式放大器（Electronics Shop，Rockefeller University），并使用连接到操纵器的Burleigh Inchworm（Burleigh Instruments，Fishers，NY）推进到小眼中。将光纤光管与小眼的光轴对准以获得最大刺激。以这种方式，我们记录细胞内的偏心细胞的反应，每5分钟提供8-s的闪光。经过一系列的控制运行，其中一个修改的鲎林格氏液灌注在切片（速率：1毫升/分钟），1 mM的组胺在盐水中的溶液被施加到切片以相同的速度。
Lateral inhibition is an integrative mechanism found in many nervous systems. In retinas, it enhances borders and edges in the visual field (1). Since its discovery in the lateral eye of the horseshoe crab, Limulus polyphemus, by H. Keffer Hartline and colleagues in 1952 (2), lateral inhibition has been studied extensively (3). It is now the foundation of a comprehensive model of retinal function (4). One question, however, remains unanswered. What is the neurotransmitter that mediates lateral inhibition in the Limulus eye? Histamine has been implicated as a photoreceptor neurotransmitter in Uniramia and Crustacea, two of the major groups of arthropods (5, 6, 7). In preparations that study the postsynaptic effects of histamine, histamine has been shown to be inhibitory (7, 8). Biochemical studies show that histamine and the enzymes that synthesize it are present in the Limulus retina (9), but provide no physiological evidence that histamine is the transmitter of lateral inhibition. In this paper, we report electrophysiological and pharmacological studies that test the role of histamine in lateral inhibition in the Limulus eye.In the first experiment, we tested whether histamine mimics the action of lateral inhibition on optic nerve activity generated by eccentric cells in individual ommatidia. To gain access to eccentric cells, we excised the lateral eye and sectioned it into three or four slices. One slice was placed in a Lucite perfusion chamber (volume 0.5 ml). A glass microelectrode filled with 3 h4 KC1 (25 MR) was connected to a DC bridge amplifier (Electronics Shop, Rockefeller University) and advanced into an ommatidium using a Burleigh Inchworm (Burleigh Instruments, Fishers, NY) attached to a manipulator. A fiber optic light pipe was aligned with the optical axis of the ommatidium for maximal stimulation. In this manner, we recorded intracellular responses of eccentric cells to 8-s light flashes delivered every 5 min. After a series of control runs in which a modified Limulus Ringer was perfused over the slice (rate: 1 ml/min), a 1 mM solution of histamine in saline was applied to the slice at the same rate.