  The enormous red-shifting of the modes during the inflationary epoch suggests
that physics at the Planck scale may modify the standard, nearly,
scale-invariant, primordial, density perturbation spectrum. Under the principle
of path-integral duality, the space-time behaves as though it has a minimal
length $L_{_{\rm P}}$ (which we shall assume to be of the order of the Planck
length), a feature that is expected to arise when the quantum gravitational
effects on the matter fields have been taken into account. Using the method of
path integral duality, in this work, we evaluate the Planck scale corrections
to the spectrum of density perturbations in the case of exponential inflation.
We find that the amplitude of the corrections is of the order of $({\cal
H}/M_{_{\rm P}})$, where ${\cal H}$ and $M_{_{\rm P}}$ denote the inflationary
and the Planck energy scales, respectively. We also find that the corrections
turn out to be completely independent of scale. We briefly discuss the
implications of our result, and also comment on how it compares with an earlier
result.
