Dendritic spines mediate most excitatory neurotransmission in the nervous system, so their function must be critical for the brain. Spines are biochemical compartments, but could also electrically modify synaptic potentials. Using two-photon microscopy and a genetically-encoded voltage indicator, we measured membrane potentials in spines and dendrites from pyramidal neurons in somatosensory cortex of mice during spontaneous activity and sensory stimulation. Spines and dendrites were depolarized together during action potentials, but, during subthreshold and resting potentials, spines often experienced different voltages than parent dendrites, even activating independently. Spine voltages remained compartmentalized after two-photon optogenetic activation of individual spine heads. We conclude that spines are elementary voltage compartments. The regulation of voltage compartmentalization could be important for synaptic function and plasticity, dendritic integration, and disease states.

中文翻译：

---

体内树突棘的电压划分

树突棘介导神经系统中的大多数兴奋性神经传递，因此它们的功能对大脑至关重要。脊柱是生化隔间，但也可以电改变突触电位。使用双光子显微镜和基因编码的电压指示器，我们测量了自发活动和感觉刺激期间小鼠体感皮层锥体神经元的棘和树突的膜电位。棘突和树突在动作电位期间一起去极化，但在阈下和静息电位期间，棘突通常经历与父树突不同的电压，甚至独立激活。在单个脊柱头部的双光子光遗传学激活后，脊柱电压保持分隔。我们得出结论，刺是基本的电压隔间。