Department of Neuro- and Sensory Physiology, University Medical Center Göttingen, Göttingen, Germany.
Center for Biostructural Imaging of Neurodegeneration, University Medical Center Göttingen, Göttingen, Germany.
Life Sci Alliance. 2024 Aug 12;7(11). doi: 10.26508/lsa.202402793. Print 2024 Nov.
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.
突触蛋白需要定期替换，以维持功能和防止损伤。目前尚不清楚这一过程（即蛋白质周转）是否与突触形态有关。为了验证这一点，我们依赖纳米级二次离子质谱法来检测年轻成年（6 个月大）和老年（24 个月大）小鼠大脑中新合成的突触成分，同时利用透射电子显微镜揭示突触形态。一些与周转相关的参数，包括突触前和突触后大小、突触小泡数量以及突触后新生区的存在。在老年小鼠中，所有脑区的周转都减少了约 20%。在老年小鼠中，突触前和突触后的周转速率相关性很好，表明它们受到共同的调节机制的影响。在年轻成年小鼠中，这种相关性较差，与它们更高的突触动态相一致。我们的结论是，突触周转反映在突触形态上。
