Habenula neurons are constantly active. The level of activity affects mood and behaviour, with increased activity in the lateral habenula reflecting exposure to punishment and a switch to passive coping and depression. Here, we identify GABAergic neurons that could reduce activity in the lateral habenula of larval zebrafish. GAD65/67 immunohistochemistry and imaging of gad1b:DsRed transgenic fish suggest the presence of GABAergic terminals in the neuropil and between cell bodies in the lateral habenula. Retrograde tracing with the lipophilic dye DiD suggests that the former derives from the thalamus, while the latter originates from a group of cells in the posterior hypothalamus that are located between the posterior tuberal nucleus and hypothalamic lobes. Two‐photon calcium imaging indicates that blue light causes excitation of thalamic GABAergic neurons and terminals in the neuropil, while a subpopulation of lateral habenula neurons show reduced intracellular calcium levels. Whole‐cell electrophysiological recording indicates that blue light reduces membrane potential of lateral habenula neurons. These observations suggest that GABAergic input from the thalamus may mediate inhibition in the zebrafish lateral habenula. Mechanisms governing release of GABA from the neurons in the posterior hypothalamus, which are likely to be in the tuberomammillary nucleus, remain to be defined.

中文翻译：

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识别支配斑马鱼侧ha的GABA能神经元。

ben神经元不断活跃。活动水平会影响情绪和行为，外侧ha管中活动的增加反映了受到惩罚并转向被动应对和抑郁。在这里，我们确定了GABA能神经元，它可以减少幼虫斑马鱼侧ha中的活动。GAD65 / 67免疫组化及gad1b：DsRed成像转基因鱼表明在神经pil中以及在外侧ha的细胞体之间存在GABA能末端。用亲脂性染料DiD进行的逆行示踪表明，前者源自丘脑，而后者源自下丘脑后部，位于后管核和下丘脑叶之间的一组细胞。双光子钙成像表明蓝光引起丘脑GABA能神经元和神经纤维末端的兴奋，而侧面ha神经元的亚群显示细胞内钙水平降低。全细胞电生理记录表明，蓝光会降低侧ha神经元的膜电位。这些观察结果表明，来自丘脑的GABA能输入可能介导了斑马鱼侧ha的抑制作用。