What resolves this contention: Whether persistent activity is primarily sustain…

What resolves this contention: Whether persistent activity is primarily sustained by NMDA-receptor-mediated recurrent excitation or by short-term presynaptic facilitation of recurrent E→E synapses in a balanced regime. / Our results supports the scenario where N-methyl-d-aspartate receptor-dependent recurrent excitation is the workhorse for the maintenance of persistent activity, whereas slow synaptic or cellular processes contribute to the robustness of mnemonic function in a tradeoff that potentially can be adjusted according to behavioral demands. / We also show that short-term synaptic facilitation can be the physiological substrate of these nonlinearities and that the resulting mechanism of balanced persistent activity is robust, in particular with respect to changes in the connectivity.