We analyze zero-lag and cluster synchrony of delay-coupled non-smooth
dynamical systems by extending the master stability approach, and apply this to
networks of adaptive threshold-model neurons. For a homogeneous population of
excitatory and inhibitory neurons we find (i) that subthreshold adaptation
stabilizes or destabilizes synchrony depending on whether the recurrent
synaptic excitatory or inhibitory couplings dominate, and (ii) that synchrony
is always unstable for networks with balanced recurrent synaptic inputs. If
couplings are not too strong, synchronization properties are similar for very
different coupling topologies, i.e., random connections or spatial networks
with localized connectivity. We generalize our approach for two subpopulations
of neurons with non-identical local dynamics, including bursting, for which
activity-based adaptation controls the stability of cluster states, independent
of a specific coupling topology.Comment: 11 pages, 5 figure