Directional Electrical Spiking, Bursting, and Propagation in Oyster Mycelium Recorded with a Star-Shaped Electrode Array

Electrical activity in fungal mycelium has been reported in numerous species and experimentalcontexts, yet its spatial organisation and propagation remain insufficiently characterised.In this study we investigate the spatiotemporal structure of electrical potential dynamics inoyster mushroom (\textit{Pleurotus ostreatus}) mycelium colonising a wood-shavings substrate.Electrical signals were recorded using an eight-channel star-shaped differential electrodearray providing angular resolution around a central region of colonised substrate. We analysespike statistics, bursting behaviour, inter-channel correlations, and event-based propagationdelays. The results reveal strong directional heterogeneity in spiking frequency and amplitude,clustered bursting dynamics, partial and localised coupling between channels, and reproduciblepropagation patterns across spatial sectors. Electrical bursts originate preferentially inspecific directions and recruit other regions with with characteristic delays ranging from seconds to minutes to hours. These findings support the interpretation of fungal mycelium as a spatiallyextended excitable medium capable of slow, distributed electrical signalling and signalintegration.