Fig. 6.

UP/DOWN dynamics in an Adapting Inhibition-Stabilized Network (aISN). a Model schematic. b r_e–r_i phase plane with a frozen. c Bistability in the aISN with a frozen. Effective I/O curve of the excitatory population rate, r_ss, with r_e–r_i phase planes at low, intermediate, and high levels of drive to the E population (Top). Parameters: w_e = 4, w_i = 3. d Excitable_UP dynamics in the aISN. Parameters: τ_e = τ_i = 5 ms, τ_a = 200 ms. e UP/DOWN transitions in the Excitable_UP aISN. (Left) Time course of the model in response to brief excitatory input to the excitatory population. f (Bottom) Trajectory of the time course in the r_e–a phase plane after stimulus-induced transition. The effective I/O curve, r_ss, and the steady state adaptation curve, A_∞(r), act like the r and a nullclines in the excitation only model. (Top) Trajectories of the stimulus-induced UP→DOWN and subsequent DOWN→UP transition in the r_e-r_i phase plane. The dotted line separates the basin of attraction for the DOWN and UP state fixed points