Discharge frequencies and intervals between pulses: are they always the same?

Neuronal discharge recorded as action potentials with intervening interpulse intervals can be converted to a frequency format. The ease of this interconversion masks two important problems in this process. For the same data set, the dynamics of change with the measured variable will be different for each of these two methods of characterizing discharge and each of these forms of rate indexing will have a different mean value. In all neuronal discharge studies, it may be initially necessary to determine whether normal population statistics apply to the primary data expressed in the IPI-mode or in the Hz-mode.