Figure 6.

A possible role of disinhibition in the generation of SWRs

(A) Top: the three-population network model consists of excitatory cells (P) and two groups of interneurons (PV BCs and anti-SWR cells, B and A, respectively). Arrows ending with a triangle show excitatory connections (exc.), and arrows ending with a circle show inhibitory connections (inh.). The connection of PV BCs to anti-SWR cells involves a mechanism of short-term synaptic depression (dark red). Bottom: schematic representation of the network behavior by a particle (gray dot) moving in a potential landscape. The network dynamics switch between non-SWR and SWR states (arrows). Text color represents the dominant interneuron type that is active in both states, i.e., dominance of B cells in the SWR state and dominance of A cells in the non-SWR state. External factors (i.e., current injection or dynamic synaptic depression) can be used to trigger transitions between the two states.

(B) Schematic of the dominant subnetworks in non-SWR and SWR states. Top: non-SWR state: the interaction between P and A cells determines the network activity, while B cells are almost silent. Despite the low firing rate of P cells, their inputs to the A cells are required to keep the A cells active. Bottom: SWR state: active P and B cells dominate the network activity, whereas A cells are almost silent. Figure modified with permission from Evangelista et al. ¹⁸²