All cells process information, but nerves/neurons are specialized to do so extremely fast in order to respond accurately, in chain reactions, in real time to inputs from perception and memory. Spikes should be really good at this, they're both very short codewords and strong electrical perturbations for neighboring neurons, but they aren't the sole information carriers that would fit the digital computer metaphor. Analog abounds
"transmembrane ion gradients potentially may encode in excess of 10^14 bits of
Shannon information"