  Neutrino is a good probe of extra dimensions. Large mixing and the apparent
lack of very complicated oscillation patterns may be an indication of large
couplings between the brane and a single bulk neutrino. A simple and realistic
five-dimensional model of this kind is discussed. It requires a sterile in
addition to three active neutrinos on the brane, all coupled strongly to one
common bulk neutrino, but not directly among themselves. Mindful that sterile
neutrinos are disfavored in the atmospheric and solar data, we demand induced
mixing to occur among the active neutrinos, but not between the active and the
sterile. The size $R$ of the extra dimension is arbitrary in this model,
otherwise it contains six parameters which can be used to fit the three
neutrino masses and the three mixing angles. However, in the model those six
parameters must be suitably ordered, so a successful fit is not guaranteed. It
turns out that not only the data can be fitted, but as a result of the
ordering, a natural connection between the smallness of the reactor angle
$\theta_{13}$ and the smallness of the mass-gap ratio $\Delta
M^2_{solar}/\Delta M^2_{atmospheric}$ can be derived.
