Spiking Neural P Systems with Several Types of Spikes

With a motivation related to gene expression, where enzymes act in series, somewhat similar to the train spikes traveling along the axons of neurons, we consider an extension of spiking neural P systems, where several types of "spikes" are allowed. The power of the obtained spiking neural P systems is investigated and the modeling of gene expression in these terms is discussed. Some further extensions are mentioned, such as considering a process of decay in time of the spikes.