Figure 5.

Firing rates of E_att and E_bkg in response to multiple input transients (“kicks,” central figure). Excitatory (inhibitory) transients are created by square-pulse increments of E1_AER (I_AER) activity. The timing of input transients is illustrated beneath the central figure: 0.5 and 1.5 s mark the onset of sub-threshold (ν_E1 = 34 Hz) and supra-threshold (ν_E1 = 67, 84, or 115 Hz) excitatory “kicks,” 3 and 4 s that of sub- and supra-threshold inhibitory “kicks.” Sub-threshold “kicks” merely modulate activity of the current meta-stable state. Supra-threshold “kicks” additionally trigger a transition to the other meta-stable state. All observations are predicted by the analysis of effective response functions (ERFs, insets on either side of central figure) measured on-chip. In the absence of input transients, the default ERF predicts two meta-stable fixed points, one “low” state (blue dot, bottom insets) and one “high” state (blue dot, top right inset). In the presence of input transients, the ERF is altered (orange, red, and burgundy curves, top-left inset) and the position of the meta-stable “high” state is shifted (orange, red, and burgundy dots).