To maximize the speed of information processing, some synapses can sustain high-frequency transmission. However, our understanding of the mechanisms of high-frequency synaptic transmission has been hampered by the limited number of synapses allowing direct recordings. Here, we exploit presynaptic recordings from cerebellar mossy fiber boutons (cMFBs) to analyze high-frequency signaling. Simultaneous remote stimulations of the mossy fiber axons can elicit action potentials at 1 kHz frequency in cMFBs with mean half-width of 150 ms and minimal action potential broadening. Furthermore, capacitance recordings at cMFB revealed that 2000 and 7000 vesicles fuse with time constants of 1.5 and 60 ms, respectively. Finally, the effective rate of vesicles reloading during high-frequency transmission is reduced when the calcium buffer EGTA is elevated in the terminal. These data suggest that a large pool of rapidly fusing vesicles permits kHz-transmission at a central synapse.