Previously, electrophysiological studies have provided the evidence that there is a Ca2+-mediated depolarization, which causes voltage-gated Na+ channels to open, resulting in action potentials.
The significance of PDS may increase the signal-to-noise ratio, and play a vital role in information processing, synaptic plasticity.
The evidence shows that there is a probable increase in intracellular calcium ions, which sustain calcium-dependent PDS.
The amount of calcium entry through ion channels is critical in determining the physiological or pathological state of individual neurons,[3]).
[citation needed] Alternatively the PDS can still occur and is less frequently studied by blocking calcium channels with heavy metals such as Ni2+.
[citation needed] If several million neurons discharge at once, it shows up on a scalp EEG as a focal interictal epileptiform spike.