[en] Transitions between highly excited atomic states involving a change of the principal quantum number which occur as the result of collisions between neutral particles and atomic core are investigated. Such transitions of a Rydberg electron are due to inertial forces acting on the electron on acceleration of the core. Another cause is the interaction with the dipole moment due to redistribution of the inner electron density during the particle collision. The state of the inner electrons during the transitions does not change. The mechanism considered is most effective when the transport cross section for scattering of the buffer gas neutrals by the ion core of a highly excited atom is large and their interaction potential is a deep well. This situation occurs, for example on relaxation of the hydrogen Rydberg states H(n) in collisions with helium atom He(1s²). It is shown that in this case the N→n' cross sections and rates are determined by the mechanism studied here and not by scattering of a weakly bound electron on a neutral particle as in the case of nl→nl' transitions involving a change of only the orbital moment