Before revision:  For spiking networks with hierarchical modular topology , we show that slow spike-train fluctuations emerge due to the increase of either  the global synaptic strength parameter or the network hierarchical level , while the network size remains constant.
After revision:  For spiking networks with hierarchical modular topology , we show that slow spike-train fluctuations emerge due to the increase of either (i) the global synaptic strength parameter or the network hierarchical level , while the network size remains constant.