  Galactic nuclei are unique laboratories for the study of processes connected
with the accretion of gas onto supermassive black holes. At the same time, they
represent challenging environments from the point of view of stellar dynamics
due to their extreme densities and masses involved. There is a growing evidence
about the importance of the mutual interaction of stars with gas in galactic
nuclei. Gas rich environment may lead to stellar formation which, on the other
hand, may regulate accretion onto the central mass. Gas in the form of massive
torus or accretion disc further influences stellar dynamics in the central
parsec either via gravitational or hydrodynamical interaction. Eccentricity
oscillations on one hand and energy dissipation on the other hand lead to
increased rate of infall of stars into the supermassive black hole. Last, but
not least, processes related to the stellar dynamics may be detectable with
forthcoming gravitational waves detectors.
