Limits to Information Transfer Through Biological Autoluminescence 

A considerable body of experimental research suggests that cells communicate using weak optical signals. While the communication between biological systems through light is common, the hypothesis that cells exchange information by means of ultraweak photon emission (UPE or biological autoluminescence) requires detailed scrutiny. Here, we discuss cell-to-cell signaling by UPE in the framework of the physical theory of communication. By comparing the signal properties of UPE with the characteristics of photoreceptive cellular mechanisms, we conclude that UPE is unlikely to play a role in biocommunication in common biological contexts. The main reason for this conclusion is that given the wavelength and intensity of UPE, cells can hardly distinguish it from ambient optical noise. This conclusion implies that alternative mechanisms can provide a more suitable explanation for experimental observations.