  The dodecaboride LuB$_{12}$ with cage-glass state and rattling modes has been
studied to clarify the nature of the large amplitude vibrations of Lu ions.
Discovered anisotropy of charge transport in conjunction with distortions of
the conventional \textit{fcc} symmetry of the crystal lattice may be attributed
to coherent motion of Lu ions along singular direction in the lattice.
Arguments are presented in favor of cooperative dynamic Jahn-Teller effect in
the boron sublattice to be the reason of the rattling mode, lattice distortion
and formation of the filamentary structure of the conductive channels.
