The incorporation of rhodopsin into lipid bilayer membranes (1bm) will be attempted by the approach of fusion of vesicles from retinal rod outer segments with preformed artificial membranes. We plan to study any light-dependent and ion-specific currents across the 1bm induced by rhodopsin. We intend to characterize the conditions for fusion of biological membranes with 1bm by using Acholeplasma laidlawii as our biomembrane. These processes will be studied by the simultaneous monitoring of the electrical characteristics of the 1bm and the fluorescence of adequate membrane probes and rhodopsin labels. We aim at a better understanding of the primary events in vision. At the same time we feel that the fusion of biological membranes with 1bm represents an ideal system for the incorporation of intrinsic membrane proteins into reconstituted lipid membranes and thus render them accessible to a sensitive observation of their function.