Abstract:
Synaptic proteins need to be replaced regularly, to maintain function and to prevent damage. It is unclear whether this process, known as protein turnover, relates to synaptic morphology. To test this, we relied on nanoscale secondary ion mass spectrometry, to detect newly synthesized synaptic components in the brains of young adult (6 mo old) and aged mice (24 mo old), and on transmission electron microscopy, to reveal synapse morphology. Several parameters correlated to turnover, including pre- and postsynaptic size, the number of synaptic vesicles and the presence of a postsynaptic nascent zone. In aged mice, the turnover of all brain compartments was reduced by ∼20%. The turnover rates of the pre- and postsynapses correlated well in aged mice, suggesting that they are subject to common regulatory mechanisms. This correlation was poorer in young adult mice, in line with their higher synaptic dynamics. We conclude that synapse turnover is reflected by synaptic morphology.
摘要:
突触蛋白需要定期更换,保持功能并防止损坏。目前还不清楚这个过程是否,被称为蛋白质周转,与突触形态有关。为了测试这个,我们依靠纳米级二次离子质谱,检测年轻成人(6个月大)和老年小鼠(24个月大)大脑中新合成的突触成分,在透射电子显微镜上,揭示突触形态。与营业额相关的几个参数,包括突触前和突触后的大小,突触小泡的数量和突触后新生区的存在。在老年小鼠中,所有脑室的营业额减少了20%。老年小鼠突触前和突触后的转换率相关性良好,这表明它们受到共同的监管机制的约束。这种相关性在年轻的成年小鼠中较差,符合他们更高的突触动力学。我们得出的结论是,突触转换是由突触形态反映的。