  Author summary: Synchronization of neuronal spiking in the brain is related
to cognitive functions, such as perception, attention, and memory. It is
therefore important to determine which properties of neurons influence their
collective behavior in a network and to understand how. A prominent feature of
many cortical neurons is spike frequency adaptation, which is caused by slow
transmembrane currents. We investigated how these adaptation currents affect
the synchronization tendency of coupled model neurons. Using the efficient
adaptive exponential integrate-and-fire (aEIF) model and a biophysically
detailed neuron model for validation, we found that increased adaptation
currents promote synchronization of coupled excitatory neurons at lower spike
frequencies, as long as the conduction delays between the neurons are
negligible. Inhibitory neurons on the other hand synchronize in presence of
conduction delays, with or without adaptation currents. Our results emphasize
the utility of the aEIF model for computational studies of neuronal network
dynamics. We conclude that adaptation currents provide a mechanism to generate
low frequency oscillations in local populations of excitatory neurons, while
faster rhythms seem to be caused by inhibition rather than excitation.
