The African wave-type electric fish, Gymnarchus niloticus, lacks corollary discharge mechanisms for electrosensory gating.
The African wave-type electric fish, Gymnarchus niloticus, lacks corollary discharge mechanisms for electrosensory gating.
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非洲波浪型电鱼 Gymnarchus niloticus 缺乏电感应门控的必然放电机制。
DOI：
10.1007/bf00193781
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发表时间：
1994
期刊：
影响因子：
--
通讯作者：
Kawasaki,M
中科院分区：
文献类型：
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作者：
Kawasaki,M
波浪型非洲电鱼Gymnarchus niloticus仅依靠传入信号进行干扰回避反应，不使用延髓起搏核的必然放电，从而产生电子器官放电的节律性。这与在近亲关系密切的非洲脉冲型电鱼中发现的感觉处理模式形成鲜明对比，在这种模式下，传入信号由起搏器的必然放电来选通，以区分传入和传入刺激。Gymnarchus是否仍然具有其他行为任务的必然放电机制，但不用于干扰回避反应？在这项研究中，我记录并标记了产生或传递电子器官放电起搏信号的延髓神经元结构，以检查这些信息是否也直接发送到任何感觉区域。起搏核团被确定为起搏信号的产生部位。起搏神经元专门投射到外侧中继核，而外侧中继核又专门投射到内侧中继核。内侧中继核中的神经元将未分枝的轴突发送到脊髓电动神经元。这些神经元完全用于驱动电子器官的放电，没有发现这些神经元的轴突侧支投射到任何感觉区域。这表明Gymnarchus不具备作为必然放电机制的神经元硬件。
Gymnarchus niloticus, a wave-type African electric fish, performs its jamming avoidance response by relying solely upon afferent signals and does not use corollary discharges from the pacemaker nucleus in the medulla which generates the rhythmicity of electric organ discharges. This is in sharp contrast to the mode of sensory processing found in closely related African pulse-type electric fishes where afferent signals are gated by corollary discharges from the pacemaker for the distinction of exafferent and reafferent stimuli. DoesGymnarchusstill possess a corollary discharge mechanism for other behavioral tasks but does not use it for the jamming avoidance response? In this study, I recorded from and labeled medullary neuronal structures that either generate or convey the pacemaker signal for electric organ discharges to examine whether this information is also sent directly to any sensory areas. The pacemaker nucleus was identified as the site of generation of the pacemaking signal. The pacemaker neurons project exclusively to the lateral relay nucleus which, in turn projects exclusively to the medial relay nucleus. Neurons in the medial relay nucleus send unbranched axons to the spinal electromotoneurons. These neurons are entirely devoted to drive the electric organ discharges, and no axon collaterals from these neurons were found to project to any sensory areas. This indicates thatGymnarchusdoes not possess the neuronal hardware for a corollary discharge mechanism.