Figure 9.

Circuit model of hippocampal–prefrontal–amygdaloid interactions in the renewal of fear. A, In this scenario, both direct and indirect projections of the VH to the BA are required for the renewal of fear after extinction. Disconnection of either the direct or indirect pathways deprives the BA of convergent input from the VH and PL. B, Another possibility is that convergence of direct and indirect projections from the VH to the PL mediate the renewal of fear. Indeed, disconnection of either the VH–PL or VH–BA projection prevents convergence of VH and BA input in the PL.