  We investigate the effective dynamics of an arbitrary Dirichlet p-brane, in a
path-integral formalism, by incorporating the massless excitations of closed
string modes in open bosonic string theory. It is shown that the closed string
background fields in the bosonic sector of type II theories induce invariant
extrinsic curvature on the world-volume. In addition, the curvature can be seen
to be associated with a divergence at the boundary of string world-sheet. The
re-normalization of the collective coordinates, next to leading order in its
derivative expansion, is performed to handle the divergence and the effective
dynamics is encoded in Dirac-Born-Infeld action. Furthermore, the collective
dynamics is generalized to include appropriate fermionic partners in type I
super-string theory. The role of string modes is reviewed in terms of the
collective coordinates and the gauge theory on the world-volume is argued to be
non-local in presence of the U(1) invariant field strength.
