Department of Biochemistry and Biophysics, Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, San Francisco, United States.
Department of Neurology, University of California, San Francisco, San Francisco, United States.
Elife. 2019 Apr 11;8:e45717. doi: 10.7554/eLife.45717.
Firing rate homeostasis (FRH) stabilizes neural activity. A pervasive and intuitive theory argues that a single variable, calcium, is detected and stabilized through regulatory feedback. A prediction is that ion channel gene mutations with equivalent effects on neuronal excitability should invoke the same homeostatic response. In agreement, we demonstrate robust FRH following either elimination of Kv4/Shal protein or elimination of the Kv4/Shal conductance. However, the underlying homeostatic signaling mechanisms are distinct. Eliminating Shal protein invokes -dependent rebalancing of ion channel gene expression including enhanced and . By contrast, expression of these genes remains unchanged in animals harboring a CRISPR-engineered, pore-blocking mutation where compensation is achieved by enhanced IK. These different homeostatic processes have distinct effects on homeostatic synaptic plasticity and animal behavior. We propose that FRH includes mechanisms of proteostatic feedback that act in parallel with activity-driven feedback, with implications for the pathophysiology of human channelopathies.
发放率稳态(FRH)稳定神经活动。一个普遍且直观的理论认为,通过调节反馈,可以检测和稳定单一变量钙。一个预测是,对神经元兴奋性具有等效影响的离子通道基因突变应该会引发相同的稳态反应。我们的实验结果一致,在消除 Kv4/Shal 蛋白或消除 Kv4/Shal 电导后,均观察到了稳健的 FRH。然而,潜在的稳态信号机制是不同的。消除 Shal 蛋白会引起依赖性离子通道基因表达的再平衡,包括增强和。相比之下,在携带 CRISPR 工程设计的、具有孔阻塞突变的动物中,这些基因的表达保持不变,其中通过增强 IK 来实现补偿。这些不同的稳态过程对稳态突触可塑性和动物行为有不同的影响。我们提出,FRH 包括蛋白稳态反馈机制,这些机制与活动驱动的反馈平行作用,这对人类通道病的病理生理学具有重要意义。