Synaptic transmission is an ultra-fast process that aims at transducing a signal from one neuron to another neuron or cell by the release of neurotransmitters. This process requires rapid response which can be transmitted through fast molecular switches such as post-translational modifications of proteins. We aimed at investigating the potential importance in dynamic modulation of sialic acids on N-linked glycoproteins that are essential for the synaptic transmission process. For this, we characterize site-specific alteration in sialylated N-linked glycosylation in the active zone of rat nerve terminals (synaptosomes) after depolarization by using quantitative sialiomics.