Kaech S, Brinkhaus H, Matus A
Friedrich Miescher Institute, P.O. Box 2543, 4002 Basel, Switzerland.
Proc Natl Acad Sci U S A. 1999 Aug 31;96(18):10433-7. doi: 10.1073/pnas.96.18.10433.
Dendritic spines form the postsynaptic contact sites for most excitatory synapses in the brain. Spines occur in a wide range of different shapes that can vary depending on an animal's experience or behavioral status. Recently we showed that spines on living neurons can change shape within seconds in a process that depends on actin polymerization. We have now found that this morphological plasticity is blocked by inhalational anesthetics at concentrations at which they are clinically effective. These volatile compounds also block actin-based motility in fibroblasts, indicating that their action is independent of neuron-specific components and thus identifying the actin cytoskeleton as a general cellular target of anesthetic action. These observations imply that inhibition of actin dynamics at brain synapses occurs during general anesthesia and that inhalational anesthetics are capable of influencing the morphological plasticity of excitatory synapses in the brain.
树突棘构成了大脑中大多数兴奋性突触的突触后接触位点。树突棘呈现出广泛的不同形状，这些形状会因动物的经历或行为状态而有所不同。最近我们发现，活神经元上的树突棘能够在数秒内改变形状，这一过程依赖于肌动蛋白聚合。我们现在发现，这种形态可塑性在吸入性麻醉剂处于临床有效浓度时会被阻断。这些挥发性化合物还会阻断成纤维细胞中基于肌动蛋白的运动，这表明它们的作用独立于神经元特异性成分，从而确定肌动蛋白细胞骨架是麻醉作用的一个通用细胞靶点。这些观察结果意味着，在全身麻醉期间大脑突触处的肌动蛋白动力学受到抑制，并且吸入性麻醉剂能够影响大脑中兴奋性突触的形态可塑性。
