Previous experiments charted the development of behavioral arousal in postnatal mice. From Postnatal Day 3 (P3) to Postnatal Day 6 (P6) mice (a) become significantly more active, “arousable”; and (b) in large reticular neurons, nucleus gigantocellularis (NGC), patch clamp recordings reveal a significantly increased ability to fire high frequency trains of action potentials as are associated with elevated cortical arousal. These action potential trains depend on delayed rectifiers such as Kv2.1. Here we report tracking the development of expression of a delayed rectifier, Kv2.1 in NGC neurons crucial for initiating CNS arousal. In tissue sections, light microscope immunohistochemistry revealed that expression of Kv2.1 in NGC neurons is greater at day P6 than at P3. Electron microscope immunohistochemistry revealed Kv2.1 labeling on the plasmalemmal surface of soma and dendrites, greater on P6 than P3. In brainstem reticular neuron cell culture, Kv2.1 immunocytochemistry increased monotonically from Days-In-Vitro 3–10, paralleling the ability of such neurons to fire action potential trains. The increase of Kv2.1 expression from P3 to P6, perhaps in conjunction with other delayed rectifier currents, could permit the ability to fire action potential trains in NGC neurons. Further work with genetically identified NGC neurons is indicated.

先前的实验描绘了出生后小鼠行为唤醒的发展。从出生后第 3 天 (P3) 到出生后第 6 天 (P6)，小鼠 (a) 变得更加活跃、“可唤醒”； (b) 在大网状神经元、巨细胞核 (NGC) 中，膜片钳记录显示，发射高频动作电位序列的能力显着增强，这与皮质唤醒的升高有关。这些动作电位序列取决于延迟整流器，例如 Kv2.1。在这里，我们报告跟踪 NGC 神经元中延迟整流器 Kv2.1 表达的发展，这对于启动 CNS 唤醒至关重要。在组织切片中，光镜免疫组织化学显示，NGC 神经元中 Kv2.1 的表达在 P6 天高于 P3。电子显微镜免疫组织化学显示体细胞和树突质膜表面有 Kv2.1 标记，P6 上的标记比 P3 上的标记更多。在脑干网状神经元细胞培养中，Kv2.1 免疫细胞化学从体外 3-10 天单调增加，与此类神经元激发动作电位序列的能力平行。 Kv2.1 表达从 P3 到 P6 的增加，可能与其他延迟整流电流结合，可能允许在 NGC 神经元中激发动作电位序列。表明了对基因鉴定的 NGC 神经元的进一步研究。