Behavioural and functional characterization of Kv10.1 (Eag1) knockout mice

Kv10.1 (Eag1), member of the Kv10 family of voltage-gated potassium channels, is preferentially expressed in adult brain. The aim of the present study was to unravel the functional role of Kv10.1 in the brain by generating knockout mice where the voltage sensor and pore region of Kv10.1 was removed to render non-functional proteins through deletion of exon 7 of the KCNH1 gene using the "3 Lox P strategy." Kv10.1-deficient mice show no obvious alterations during embryogenesis and develop normally to adulthood; cortex, hippocampus and cerebellum appear anatomically normal. Other tests, including general health screen, sensorimotor functioning and gating, anxiety, social behaviour, learning and memory did not show any functional aberrations in Kv10.1 null mice. Kv10.1 null mice display mild hyperactivity and longer-lasting haloperidol-induced catalepsy, but there was no difference between genotypes in amphetamine sensitisation and withdrawal, reactivity to apomorphine and haloperidol in the prepulse inhibition tests or to antidepressants in the haloperidol-induced catalepsy. Furthermore, electrical properties of Kv10.1 in cerebellar Purkinje cells did not show any difference between genotypes. Bearing in mind that Kv10.1 is overexpressed in over 70% of all human tumours and that its inhibition leads to a reduced tumour cell proliferation, the fact that deletion of Kv10.1 does not show a marked phenotype is a prerequisite for utilising Kv10.1 blocking and/or reduction techniques, such as siRNA, to treat cancer. 4 mice each for control wildtype and knockout miceKv10.1（Eag1）属于电压门控钾通道Kv10家族成员，在成体脑组织中特异性高表达。本研究旨在通过“3 LoxP策略”敲除KCNH1基因的第7号外显子，移除Kv10.1的电压感受器与孔道区域，使其编码的蛋白失去功能，以此构建Kv10.1基因敲除小鼠，解析Kv10.1在中枢神经系统中的功能角色。 Kv10.1缺陷小鼠在胚胎发育阶段无明显异常，可正常发育至成年；其大脑皮层、海马体与小脑的解剖结构均未见显著异常。 多项其他检测包括一般健康筛查、感觉运动功能与门控行为评估、焦虑样行为、社交行为、学习与记忆能力检测均未发现Kv10.1全敲除小鼠存在任何功能异常。 Kv10.1全敲除小鼠表现出轻度多动症状，以及氟哌啶醇诱导的僵住症持续时间延长，但在苯丙胺敏化与戒断反应、前脉冲抑制（prepulse inhibition）实验中对阿扑吗啡与氟哌啶醇的反应性，以及氟哌啶醇诱导僵住症模型中对抗抑郁药的反应性方面，两种基因型小鼠均无显著差异。此外，小脑浦肯野细胞中Kv10.1的电生理特性在两种基因型小鼠间亦无明显差异。 鉴于Kv10.1在超过70%的人类肿瘤中存在过表达，且抑制Kv10.1可降低肿瘤细胞增殖能力，那么Kv10.1基因敲除未出现明显表型这一事实，便成为利用Kv10.1阻断或敲减技术（如小干扰RNA（siRNA））治疗癌症的必要前提。本实验每组各设置4只野生型对照小鼠与4只Kv10.1敲除小鼠。