Fig 5. Comparison between fast, slow or ultraslow T-type calcium channel activation in generating robust mean-field activity transition.

A: A 200-cell network with 100 excitatory neurons and 100 inhibitory neurons connected via AMPA, GABA_A and GABA_B synapses under the control of an hyperpolarizing current. The intrinsic and extrinsic parameters are respectively affected by neuromodulation and synaptic plasticity; their values are randomly picked in a given interval (namely variability). The CaT channel activation time constant ${\tau }_{m_{CaT}}$ of each neuron is scaled by a multiplicative factor. B: At each scaled time constant, we check if the heterogeneous network is switching by analyzing the LFP activity. If the LFP timecourse presents a strong activity and its spectrogram shows a marked power band, the network displays an oscillatory state during the hyperpolarization state. C: The table summarizes the largest variability width at which the network presents a switch in its mean-field activity for several scaled time constants. Respecting the slow timescale of the CaT channel activation guarantees the switch in network rhythm compatible with variability in channel densities and synaptic weights. Driving the CaT channel activation to a fast or ultraslow timescale makes models more fragile to network topology and heterogeneity.