Recently, a new mechanism of cell-to-cell communication was

proposed when thin tubular connections between membrane-

enclosing compartments were discovered (Fig. 17.1). The basic

research was first performed on liposomes where membranous

tubes of thickness below a micrometre are commonly formed,

especially if a mechanical or a chemical disturbance is introduced

into the liposome system (Kralj-Iglicˇ et al., 2001a; Kralj-Iglicˇ, 2002;

Mathivet et al., 1996). Such lipid bilayer nanotubes may connect two

or more liposomes (Karlsson et al., 2001). It was observed (Iglicˇ

et al., 2003) that a dilatation of the tube forming a gondola may exist

and travel along the tube (Fig. 17.2).