Ladewig T, Keller B U
Zentrum Physiologie und Pathophysiologie, Universität Göttingen, Germany.
Pflugers Arch. 2000 Jun;440(2):322-32. doi: 10.1007/s004240000277.
Intracellular calcium signals are critical for modulation of neuronal function, and also for pathophysiological states during human neurodegenerative disease, such as Morbus Alzheimer and amyotrophic lateral sclerosis (ALS). We investigated intracellular calcium signals in motoneurones of the nucleus hypoglossus from the mouse, which were maintained in a functionally intact state of rhythmic, respiratory-related activity. Simultaneous patch-clamp recordings and calcium imaging demonstrated that rhythmic inspiratory-related clusters of action potential (AP) discharges are paralleled by calcium oscillations both in somatic and dendritic compartments. Calcium oscillations resulted primarily from the AP-induced opening of voltage-dependent calcium channels in the soma and dendrites. Dendritic calcium transients differed from somatic responses in their kinetics, amplitude, voltage dependence and regulation of basal calcium levels. Based on a combination of infrared differential interference contrast optics, microfluorimetric calcium imaging and electrophysiological patch-clamp recordings, our results demonstrate that the brainstem slice preparation is an attractive model system to study the integration and superposition of calcium signals in a functionally intact neuronal net.
细胞内钙信号对于调节神经元功能至关重要，在人类神经退行性疾病（如阿尔茨海默病和肌萎缩侧索硬化症，即ALS）的病理生理状态中也起着关键作用。我们研究了来自小鼠舌下神经核运动神经元的细胞内钙信号，这些神经元保持着与呼吸相关的节律性活动的功能完整状态。同时进行的膜片钳记录和钙成像表明，在躯体和树突区域，与吸气相关的节律性动作电位（AP）发放簇与钙振荡同时出现。钙振荡主要源于动作电位诱导的躯体和树突中电压依赖性钙通道的开放。树突钙瞬变在动力学、幅度、电压依赖性以及基础钙水平调节方面与躯体反应不同。基于红外微分干涉对比光学、微量荧光钙成像和电生理膜片钳记录的结合，我们的结果表明，脑干脑片制备是研究功能完整的神经元网络中钙信号整合与叠加的一个有吸引力的模型系统。
