Figure 3
From: The birth, death and resurrection of avoidance: a reconceptualization of a troubled paradigm
Neural circuits underlying defensive reactions (freezing) and actions (avoidance). The behavioral illustrations show the performance of previously acquired reactions (freezing) and actions (avoidance). (a) Reactive freezing is underpinned by a progression of information through the amygdala. Information about the auditory conditioned stimulus (CS) arrives in the lateral amygdala (LA) from auditory thalamus and/or cortex. CS information then proceeds to the central amygdala (CeA), either directly through LA projections to the central lateral CeA (CL), or indirectly via the basal amygdala (BA) and/or the intercalated cell masses (ITC). Medial CeA (M) projections to the brainstem coordinate CS-evoked reactions, such as freezing. (b) Active avoidance is underpinned by a different amygdalar output pathway. CS information is processed through LA and BA, before progressing to the nucleus accumbens (NAcc), which supports CS-prompted actions, such as shuttling to avoid. This behavior is regulated by the infralimbic prefrontal cortex (PFCIL), which suppresses CeA-mediated freezing.
