One of the unsolved puzzles of the brain is the question which code is being used when nerve cells communicate with each other. It has been known for more than a century that the basic unit of communication within the nervous system is the pulse-like fluctuation in voltage at the membrane of neurons. But there is still a hot ongoing debate on how these so-called action potentials are combined to form a code for the actual processing and transmission of information. Two forms of coding are popular candidates: one is based on the rate of action potentials (rate coding) and the other relies on the timing of their occurrences (temporal coding).
Researchers now propose that under certain conditions, both forms of coding can in fact be employed simultaneously.
Here is the full article spiking activity propagation in neuronal networks