Ionic currents that contribute to a sexually dimorphic communication signal in weakly electric fish.
Ionic currents that contribute to a sexually dimorphic communication signal in weakly electric fish.
复制标题
离子电流有助于弱电鱼产生两性异形通讯信号。
DOI：
10.1007/s003590050398
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发表时间：
1999
期刊：
影响因子：
--
通讯作者：
Smith,GT
中科院分区：
文献类型：
--
作者：
Smith,GT
弱电鱼产生通信信号，电器官放电，这是物种特异性的，在许多物种中，两性异形。由于控制电器官放电的神经回路相对简单，因此它是研究节律行为的生物物理机制和性二态行为的神经内分泌控制的一个很好的模型。通过研究离子通道阻滞剂对延髓起搏器核神经元的影响，我的特点是三个离子电流，影响起搏器的节奏，从而电器官放电频率，在gymnotiform鱼，Apteronotus leptorhynchus。这些电流包括河豚毒素敏感的钠电流;对4-氨基吡啶敏感的钾电流;和对镍和镉敏感但对L-、N-、P-和Q-型钙电流的特异性阻断剂具有抗性的钙电流。起搏核中的离子电流的药理学概况与其他神经元振荡器中参与起搏的离子电流的药理学概况相似。因为这些离子电流显著影响起搏器放电频率，而起搏器放电频率与电器官放电频率直接相关，所以这些离子电流可能是类固醇激素在电器官放电频率中产生性二态性的作用的靶点。需要进一步的研究，以确定这些离子电流如何相互作用，以产生电器官放电的节奏，并调查的可能性，在电器官放电的两性异形的结果从性腺类固醇的行动，这些离子电流。
Weakly electric fish produce a communication signal, the electric organ discharge, that is species specific, and in many species, sexually dimorphic. Because the neural circuit that controls the electric organ discharge is relatively simple, it is an excellent model in which to study both the biophysical mechanisms underlying a rhythmic behavior and the neuroendocrine control of a sexually dimorphic behavior. By studying the effects of ion channel blockers on neurons in the medullary pacemaker nucleus, I pharmacologically characterized three ionic currents that influence the pacemaker rhythm, and thus electric organ discharge frequency, in the gymnotiform fish,Apteronotus leptorhynchus. These currents included a tetrodotoxin-sensitive sodium current; a potassium current that was sensitive to 4-aminopyridine; and a calcium current that was sensitive to nickel and cadmium, but resistant to specific blockers of L-, N-, P-, and Q-type calcium currents. The pharmacological profiles of the ionic currents in the pacemaker nucleus are similar to those of ionic currents involved in pacemaking in other neuronal oscillators. Because these ionic currents dramatically influence pacemaker firing frequency, which is directly related to electric organ discharge frequency, these ionic currents are likely targets of steroid hormone action in producing sexual dimorphisms in electric organ discharge frequency. Additional studies are needed to determine how these ionic currents interact to generate the electric organ discharge rhythm and to investigate the possibility that sexual dimorphism in the electric organ discharge results from the actions of gonadal steroids on these ionic currents.