Neuronal synaptic architecture revealed by cryo-correlative light and electron microscopy.

Cryo-correlative light and electron microscopy (cryo-CLEM) is a powerful technique that combines fluorescence imaging for specific localization with electron microscopy for detailed structural analysis, enabling high-resolution exploration of synaptic structures in neurons. In this study, we employed a cryo-CLEM approach using three independent alignment markers to precisely correlate electron microscopy (EM) images with light microscopy (LM) images of neuronal synapses under cryogenic conditions. This methodology revealed a distinctive pattern of electron densities in the synaptic clefts. Additionally, we were able to capture high-resolution images of presynaptic vesicles in various states, underscoring the potential of cryo-CLEM in advancing synaptic research.