  This work is devoted to Bloch oscillations (BO) of cold neutral atoms in
optical lattices. After a general introduction to the phenomenon of BO and its
realization in optical lattices, we study different extentions of this problem,
which account for recent developments in this field. These are two-dimensional
BO, decoherence of BO, and BO in correlated systems. Although these problems
are discussed in relation to the system of cold atoms in optical lattices, many
of the results are of general validity and can be well applied to other systems
showing the phenomenon of BO.
