  F. Scardigli and R. Casadio have considered uncertainty principles which take
into account the role of gravity and possible existence of extra spatial
dimensions. They have argued that the predicted number of degrees of freedom
enclosed in a given spatial volume matches the holographic counting only for
one of the available generalization and without extra dimensions. Taking into
account the additional inevitable source of uncertainty in distance
measurement, which is missed in their approach, we show that the holographic
properties of the proposed uncertainty principle is recovered in the models
with extra spatial dimensions.
