We study the emergence of synchronized burst activity in networks of neuron
s with spike adaptation. We show that networks of tonically firing adapting
excitatory neurons can evolve to a state where the neurons burst in a sync
hronized manner. The mechanism leading to this burst activity is analyzed i
n a network of integrate-and-fire neurons with spike adaptation. The depend
ence of this state on the different network parameters is investigated, and
it is shown that this mechanism is robust against inhomogeneities, sparsen
ess of the connectivity, and noise. In networks of two populations, one exc
itatory and one inhibitory, we show that decreasing the inhibitory feedback
can cause the network to switch from a tonically active, asynchronous stat
e to the synchronized bursting state. Finally, we show that the same mechan
ism also causes synchronized burst activity in networks of more realistic c
onductance-based model neurons.