参与 NMDA 诱导的中枢杏仁核促肾上腺皮质激素释放激素神经元 M 型通道抑制的信号通路。
Signaling pathways involved in NMDA-induced suppression of M-channels in corticotropin-releasing hormone neurons in central amygdala.
机构信息
Department of Medicine, Center for Precision Medicine, School of Medicine University of Missouri, Columbia, Missouri, USA.
Departments of Pharmacology and Toxicology and Internal Medicine, The University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA.
出版信息
J Neurochem. 2022 Jun;161(6):478-491. doi: 10.1111/jnc.15647. Epub 2022 May 30.
Glutamate N-methyl-d-aspartate (NMDA) receptors (NMDARs) and Kv7/M channels are importantly involved in regulating neuronal activity involved in various physiological and pathological functions. Corticotropin-releasing hormone (CRH)-expressing neurons in the central nucleus of the amygdala (CeA) critically mediate autonomic response during stress. However, the interaction between NMDA receptors and Kv7/M channels in the CRH neurons remains unclear. In this study, we identified rat CRH neurons through the expression of an AAV viral vector-mediated enhanced green fluorescent protein (eGFP) driven by the rat CRH promoter. M-currents carried by Kv7/M channels were recorded using the whole-cell patch-clamp approach in eGFP-tagged CRH neurons in brain slices. Acute exposure to NMDA significantly reduced M-currents recorded from the CRH neurons. NMDA-induced suppression of M-currents was eliminated by chelating intracellular Ca , supplying phosphatidylinositol 4,5-bisphosphate (PIP2) intracellularly, or blocking phosphoinositide3-kinase (PI3K). In contrast, inhibiting protein kinase C (PKC) or calmodulin did not alter NMDA-induced suppression of M-currents. Sustained exposure of NMDA decreased Kv7.3 membrane protein levels and suppressed M-currents, while the Kv7.2 expression levels remained unaltered. Pre-treatment of brain slices with PKC inhibitors alleviated the decreases in Kv7.3 and reduction of M-currents in CRH neurons induced by NMDA. PKC inhibitors did not alter Kv7.2 and Kv7.3 membrane protein levels and M-currents in CRH neurons. These data suggest that transient activation of NMDARs suppresses M-currents through the Ca -dependent PI3K-PIP2 signaling pathway. In contrast, sustained activation of NMDARs reduces Kv7.3 protein expression and suppresses M-currents through a PKC-dependent pathway.
谷氨酸 N-甲基-D-天冬氨酸 (NMDA) 受体 (NMDAR) 和 Kv7/M 通道在调节各种生理和病理功能中涉及的神经元活动中起着重要作用。杏仁中央核 (CeA) 中的促肾上腺皮质激素释放激素 (CRH) 表达神经元在应激期间关键地介导自主反应。然而,CRH 神经元中的 NMDA 受体和 Kv7/M 通道之间的相互作用尚不清楚。在这项研究中,我们通过 AAV 病毒载体介导的增强型绿色荧光蛋白 (eGFP) 的表达鉴定了大鼠 CRH 神经元,该蛋白由大鼠 CRH 启动子驱动。在脑片的 eGFP 标记的 CRH 神经元中,使用全细胞膜片钳技术记录 Kv7/M 通道介导的 M 电流。急性暴露于 NMDA 可显著减少从 CRH 神经元记录的 M 电流。NMDA 诱导的 M 电流抑制作用可通过螯合细胞内 Ca 、提供细胞内磷脂酰肌醇 4,5-二磷酸 (PIP2) 或阻断磷酸肌醇 3-激酶 (PI3K) 消除。相比之下,抑制蛋白激酶 C (PKC) 或钙调蛋白不会改变 NMDA 诱导的 M 电流抑制。持续暴露于 NMDA 可降低 Kv7.3 膜蛋白水平并抑制 M 电流,而 Kv7.2 的表达水平保持不变。脑片的 PKC 抑制剂预处理可减轻 NMDA 诱导的 CRH 神经元中 Kv7.3 的减少和 M 电流的降低。PKC 抑制剂不会改变 CRH 神经元中的 Kv7.2 和 Kv7.3 膜蛋白水平和 M 电流。这些数据表明,NMDA 受体的瞬时激活通过 Ca 依赖性 PI3K-PIP2 信号通路抑制 M 电流。相反,NMDA 受体的持续激活通过 PKC 依赖性途径降低 Kv7.3 蛋白表达并抑制 M 电流。