Figure 1

The fidelity and velocity in the propagation of sequential spikes are measured on the main axons of cerebellar Purkinje cells (PC). A) Left panel shows the diagram of a whole-cell recording on PC soma and a loose-patch recording on its axonal bleb. Right panel is a neurobiotin-labeled PC whose main axon extends to deep cerebellar nucleus. B) Top trace shows axonal spikes recorded by a loose-patch on axonal bleb, bottom trace shows spikes recorded by a whole-cell recording pipette at PC soma, and middle trace shows the dV/dt values of somatic spikes. Somatic spikes are induced by sequential depolarization pulses at 200 Hz. Spike propagation is defined as a failure if axonal spikes are lower than three times of standard deviation of mean baseline value (red lines & arrows). C) Top trace shows the expanded axonal spikes recorded by a loose-patch on axonal bleb and bottom trace shows the dV/dt values of somatic spikes. The difference of their peak time is called as the delay, which is used to calculate the velocity that is equal to the division of axonal length by time delay.