  We study neutral black branes with flat and curved worldvolumes in the
presence of a negative cosmological constant. We reduce the equations governing
the dynamics of such objects to one second--order ODE and perform various
asymptotic expansions of the resulting equation. We also analyze regular
geometries which have the same symmetries as the branes and interpolate between
an empty interior and AdS asymptotics. We show that the dynamics of such
spacetimes is governed by the Abel equation.
