Cerebral CBM1 neuron contributes to synaptic modulation appearing during rejection of seaweed in Aplysia kurodai
Cerebral CBM1 neuron contributes to synaptic modulation appearing during rejection of seaweed in Aplysia kurodai
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DOI：
10.1152/jn.00757.2001
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发表时间：
2002-11-01
影响因子：
2.5
通讯作者：
Nagahama, T
中科院分区：
文献类型：
--
作者：
Narusuye, K;Nagahama, T
日本种Aaprosia kurodai以石莼为食，但拒绝石花菜，其下颚和齿舌的运动具有独特的节奏模式。我们以前已经表明，模式化的下颌运动期间拒绝石花菜可能是由持久的抑制的单突触传递的多作用MA神经元的下颌关闭（JC）运动神经元在颊神经节和调制可能直接产生的一些大脑神经元。在本文中，我们确定了一对儿茶酚胺能神经元（CBM 1）在双侧大脑M簇。CBM 1可能与A. californica，同时产生单突触兴奋性突触后电位（EPSP）的MA和JC神经元。CBM 1的放电减少了JC神经元中由MA尖峰诱发的抑制性突触后电流（IPSC）的大小，持续>100 s。此外，多巴胺的应用模拟了CBM 1的调节作用，并且用D1拮抗剂SCH 23390预处理，阻断了多巴胺诱导的调节作用。它还可以在很大程度上阻断由CBM 1放电引起的调制效应。这些结果表明，CBM 1可能通过释放多巴胺直接调节突触传递。此外，我们探讨了CBM 1峰活动的味觉刺激的动物嘴唇与海藻提取物通过使用钙成像。使用微电极将钙敏感染料钙绿色-1离子电渗加载到CBM 1的细胞体中。应用石莼或石花菜提取物的嘴唇增加了荧光强度，但石花菜提取物总是诱导荧光的变化较大的石莼提取物相比，虽然所使用的解决方案诱导的最大尖峰响应的CBM 1的海藻提取物。当估计味觉刺激后的CBM 1活性的放电频率时，石花菜提取物诱导了类似于30个尖峰/s的尖峰活性，而石莼提取物诱导了类似于20个尖峰/s的活性，这与突触调制的有效放电频率（>25个尖峰/s）一致。这些结果表明，CBM 1可能是脑神经元之一，有助于调制的基本喂养电路的排斥反应所诱导的海藻，如石花菜的味道。
The Japanese species Aplysia kurodai feeds well on Ulva but rejects Gelidium with distinctive rhythmic patterned movements of the jaws and radula. We have previously shown that the patterned jaw movements during the rejection of Gelidium might be caused by long-lasting suppression of the monosynaptic transmission from the multiaction MA neurons to the jaw-closing (JC) motor neurons in the buccal ganglia and that the modulation might be directly produced by some cerebral neurons. In the present paper, we have identified a pair of catecholaminergic neurons (CBM1) in bilateral cerebral M clusters. The CBM1, probably equivalent to CBI-1 in A. californica, simultaneously produced monosynaptic excitatory postsynaptic potentials (EPSPs) in the MA and JC neurons. Firing of the CBM1 reduced the size of the inhibitory postsynaptic currents (IPSCs) in the JC neuron, evoked by the MA spikes, for >100 s. Moreover, the application of dopamine mimicked the CBM1 modulatory effects and pretreatment with a D1 antagonist, SCH23390, blocked the modulatory effects induced by dopamine. It could also largely block the modulatory effects induced by the CBM1 firing. These results suggest that the CBM1 may directly modulate the synaptic transmission by releasing dopamine. Moreover, we explored the CBM1 spike activity induced by taste stimulation of the animal lips with seaweed extracts by the use of calcium imaging. The calcium-sensitive dye, Calcium Green-1, was iontophoretically loaded into a cell body of the CBM1 using a microelectrode. Application of either Ulva or Gelidium extract to the lips increased the fluorescence intensity, but the Gelidium extract always induced a larger change in fluorescence compared with the Ulva extract, although the solution used induced the maximum spike responses of the CBM1 for each of the seaweed extracts. When the firing frequency of the CBM1 activity after taste stimulation was estimated, the Gelidium extract induced a spike activity of similar to30 spikes/s while the Ulva extract induced an activity of similar to20 spikes/s, consistent with the effective firing frequency (>25 spikes/s) for the synaptic modulation. These results suggest that the CBM1 may be one of the cerebral neurons contributing to the modulation of the basic feeding circuits for rejection induced by the taste of seaweeds such as Gelidium.