Conductance of artificial phospholipid bilayers modified by membrane fragments of brain cortex was studied. For incorporation of the membrane fragments into bilayer the method of fusion of planar membrane with liposomes modified by the brain microsome fraction (proteoliposomes) was used. Artificial phospholipid membrane conductance increased during their interaction with proteoliposomes. Current-voltage curves of planar bilayers show that their permeability for sodium is promoted by the action of veratrine and inhibited by the action of tetrodotoxin.