A single oscillating proto-hypothalamic neuron gates taxis behavior in the primitive chordate Ciona.
A single oscillating proto-hypothalamic neuron gates taxis behavior in the primitive chordate Ciona.
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单个振荡的原下丘脑神经元控制着原始脊索动物海鞘的滑行行为。
DOI：
10.1101/2023.04.24.538092
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发表时间：
2023
期刊：
影响因子：
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通讯作者：
Smith,WilliamC
中科院分区：
文献类型：
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作者：
Chung,Janeva;Newman-Smith,Erin;Kourakis,MatthewJ;Miao,Yishen;Borba,Cezar;Medina,Juan;Laurent,Tao;Gallean,Benjamin;Faure,Emmanuel;Smith,WilliamC
被囊玻璃海鞘是唯一一种具有完整描述的连接体的脊索动物。一些幼虫行为背后的最小电路已经被描述，包括负趋光性。在玻璃海鞘幼虫，负趋光性启动通过有节奏的自发铸造游泳。当幼虫在光场中投射时，它们的光感受器将在色素细胞的帮助下被定向遮蔽，提供趋光性线索。我们在这里报告，玻璃海鞘的幼虫前脑有一个以前没有特征的单一的缓慢振荡抑制神经元（神经元BVIN 78），项目的中脑，在那里它的目标是被称为感光中继神经元的趋光性电路的关键中间神经元。BVIN 78的解剖位置、基因表达和振荡表明与脊椎动物下丘脑的振荡神经元同源。BVIN 78的消融导致幼虫表现出模仿趋光性的自发游泳，但这种游泳发生在没有趋光性线索的情况下。因此，BVIN 78通过向电路投射时间振荡抑制而对趋光性具有门控活性。BVIN 78振荡的频率与节律性自发游泳的频率不匹配，表明它并不启动游泳，而是在时间上调节它们。我们推测，它的功能是增加噪音，否则将是可预测的行为。
The tunicate Ciona is the only chordate with a fully-described connectome. Minimal circuits underlying a number of larval behaviors have been described, including for negative phototaxis. In Ciona larvae, negative phototaxis initiates via rhythmic spontaneous casting swims. As the larvae cast in a light field, their photoreceptors will be directionally shaded with the aid of a pigment cell, providing a phototactic cue. We report here that the larval forebrain of Ciona has a previously uncharacterized single slow-oscillating inhibitory neuron (neuron BVIN78) that projects to the midbrain, where it targets key interneurons of the phototaxis circuit known as the photoreceptor relay neurons. The anatomical location, gene expression and oscillation of BVIN78 indicate homology to oscillating neurons of the vertebrate hypothalamus. Ablation of BVIN78 results in larvae showing spontaneous swims that mimic phototaxis, but which occur in the absence of phototactic cues. Thus, BVIN78 has a gating activity on phototaxis by projecting temporally oscillating inhibition to the circuit. The frequency of BVIN78 oscillation does not match that of the rhythmic spontaneous swims, indicating that it does not initiate swims, but rather modulates them temporally. We speculate that its function is to add noise to what would otherwise be predictable behavior.