  Electrical activity of fungus \emph{Pleurotus ostreatus} is characterised by
slow (hours) irregular waves of baseline potential drift and fast (minutes)
action potential likes spikes of the electrical potential. An exposure of the
mycelium colonised substrate to a chloroform vapour lead to several fold
decrease of the baseline potential waves and increase of their duration. The
chloroform vapour also causes either complete cessation of spiking activity or
substantial reduction of the spiking frequency. Removal of the chloroform
vapour from the growth containers leads to a gradual restoration of the
mycelium electrical activity.
