Tuning electrical spiking of Schizophyllum commune with light

When studying the split-gill fungus Schizophyllum commune, we observed that the growing colonies displayed endogenous spikes of electrical potential similar to the action potentials of neurons. In order to investigate the impact of light on the electrical activities of these colonies, we exposed them to intermittent stimulation with cold light (5800k) and later with blue (c. 470nm), red (c. 642nm) and green (c. 538nm) light. Our findings revealed spiking activity can be influenced using this input including observable responses with patterns of spiking at relatively high average amplitudes (>1mV) appearing consistently upon illumination of the sample. The response is likely related to the activity of fungal photoreceptors, including potential sensitisation to blue light in the cellular signalling pathways facilitated by white collar proteins (WC-1, WC-2) in S. commune. Based on these findings, we suggest that fungal photosensors and photonic computing substrates have the potential to enable applications beyond the scope of conventional electronics via relatively fast spiking responses to light tuned by external input stimulation. Further work should focus on identifying the signal transduction pathway for responses to different wavelengths of light and its role in translation into engineered ELMs to extend existing studies in fungal photobiology.