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Exact neural mass model for synaptic-based working memory

Fig 3

Memory loading, maintenance and rehearsal.

The results of three experiments are reported here for different background currents: selective reactivation of the target population (I_B = 1.2, A); WM maintenance via spontaneous reactivation of the target population (I_B = 1.532, B) and via a persistent asynchronous activity (I_B = 2, C). Raster plots of the network activity for the first (blue, A1-C1) and second (orange, A3-C3) excitatory population; here the activity of only 400 neurons over 200,000 ones is shown for each population. Profiles of the stimulation current for the first (A2-C2) (second (A4-C4)) excitatory population. Population firing rates r_k(t) (A5-C5), normalized available resources (A6-C6) and normalized utilization factors (A7-C7) of the excitatory populations calculated from the simulations of the neural mass model (solid line) and of the network (shading). Spectrograms of the mean membrane potentials v₁(t) (A8-C8), v₂(t) (A9-C9), and v₀(t) (A10-C10) obtained from the neural mass model; for clarity the frequencies in these three cases have been denoted as f₁, f₂ and f₀, respectively. Red arrows in columns (B) and (C) indicate the time t = 2.15 s at which the background current is set to the value I_B = 1.2 employed in column (A). The network simulations have been obtained by considering three populations of N = 200, 000 neurons each (for a total of 600,000 neurons) arranged with the architecture displayed in Fig 2. Other parameters: ms H⁽ⁱ⁾ = H^(e) = 0, Δ⁽ⁱ⁾ = Δ^(e) = 0.1, , , , , with a = 0.4.

doi: https://doi.org/10.1371/journal.pcbi.1008533.g003