Stress-induced translation of KCNB1 contributes to the enhanced synaptic transmission of the lateral habenula. Stress-induced translation of KCNB1 contributes to the enhanced synaptic transmission of the lateral habenula

The lateral habenula (LHb) is a well-established brain region involved in depressive disorders. Synaptic transmission of the LHb neurons is known to be enhanced by stress exposure; however, little is known about genetic modulators within the LHb that respond to stress. Using recently developed molecular profiling methods by phosphorylated ribosome capture, we obtained transcriptome profiles of stress responsive LHb neurons during acute physical stress. Among such genes, we found that KCNB1 (Kv2.1 channel), a delayed rectifier and voltage-gated potassium channel, exhibited increased expression following acute stress exposure. To determine the roles of KCNB1 on LHb neurons during stress, we injected short hairpin RNA (shRNA) against the kcnb1 gene to block its expression prior to stress exposure. We observed that the knockdown of KCNB1 altered the basal firing pattern of LHb neurons. Although KCNB1 blockade did not rescue despair-like behaviors in acute learned helplessness (aLH) animals, we found that KCNB1 knockdown prevented the enhancement of synaptic strength in LHb neuron after stress exposure. This study suggests that KCNB1 may contribute to shape stress responses by regulating basal firing patterns and neurotransmission intensity of LHb neurons. Overall design: Taking advantage of the newly developed selective capturing technique of phosphorylated ribosomes, we aimed to obtain an unbiased molecular profile of the activated LHb during acute physical foot shock stress. The total sample contained all mRNAs in LHb neurons and the IP sample contained mRNAs which are combined with phosphorylated ribosome to transcript

外侧缰核（lateral habenula, LHb）是已被广泛证实与抑郁障碍相关的脑区。已知应激暴露可增强LHb神经元的突触传递，但目前对LHb内响应应激的遗传调控因子仍知之甚少。本研究借助新近开发的磷酸化核糖体捕获分子谱分析技术，获取了急性躯体应激期间响应应激的LHb神经元的转录组谱。在这些基因中，我们发现KCNB1（Kv2.1通道）——一种延迟整流型电压门控钾通道——在急性应激暴露后表达量上调。为明确KCNB1在应激状态下对LHb神经元的作用，我们在应激暴露前注射了靶向kcnb1基因的短发夹RNA（short hairpin RNA, shRNA）以阻断其表达。我们观察到，KCNB1基因敲低会改变LHb神经元的基础放电模式。尽管KCNB1阻断未能挽救急性习得性无助（acute learned helplessness, aLH）模型动物的类绝望行为，但我们发现KCNB1敲低可阻止应激暴露后LHb神经元突触强度的增强。本研究表明，KCNB1可能通过调控LHb神经元的基础放电模式与神经传递强度，参与塑造应激应答过程。整体实验设计：借助新近开发的磷酸化核糖体选择性捕获技术，本研究旨在获取急性躯体足底电击应激期间活化LHb的无偏倚分子谱。总样本包含LHb神经元内的全部mRNA，而免疫沉淀（IP）样本则包含与磷酸化核糖体结合进行转录的mRNA。