Johns Hopkins Zanvyl Krieger Mind/Brain Institute, Johns Hopkins University, Rm. 350 Dunning Hall, 3400 N. Charles St., Baltimore, MD 21218, USA; The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University, 3400 N. Charles St., Baltimore, MD 21218, USA.
Department of Biology, Johns Hopkins University, 3400 N. Charles St., Baltimore, MD 21218, USA.
Cell Rep. 2024 Oct 22;43(10):114744. doi: 10.1016/j.celrep.2024.114744. Epub 2024 Sep 17.
Capacitance of biological membranes is determined by the properties of the lipid portion of the membrane as well as the morphological features of a cell. In neurons, membrane capacitance is a determining factor of synaptic integration, action potential propagation speed, and firing frequency due to its direct effect on the membrane time constant. Besides slow changes associated with increased morphological complexity during postnatal maturation, neuronal membrane capacitance is considered a stable, non-regulated, and constant magnitude. Here we report that, in two excitatory neuronal cell types, pyramidal cells of the mouse primary visual cortex and granule cells of the hippocampus, the membrane capacitance significantly changes between the start and the end of a daily light-dark cycle. The changes are large, nearly 2-fold in magnitude in pyramidal cells, but are not observed in cortical parvalbumin-expressing inhibitory interneurons. Consistent with daily capacitance fluctuations, the time window for synaptic integration also changes in pyramidal cells.
细胞膜的电容取决于膜的脂质部分的特性以及细胞的形态特征。在神经元中，由于膜时间常数对其直接影响，因此膜电容是突触整合、动作电位传播速度和放电频率的决定因素。除了与出生后成熟过程中形态复杂性增加相关的缓慢变化外，神经元膜电容被认为是稳定的、无调节的和恒定的幅度。在这里，我们报告在两种兴奋性神经元细胞类型中，即小鼠初级视觉皮层的锥体神经元和海马的颗粒细胞中，细胞膜电容在每日光-暗循环的开始和结束之间发生显著变化。这种变化幅度很大，在锥体神经元中几乎达到 2 倍，但在表达皮质 Parvalbumin 的抑制性中间神经元中观察不到。与每日电容波动一致，锥体神经元中的突触整合时间窗口也发生变化。
