During the CS+, BLA gamma is strongly coupled to local theta, whereas during the CS−, it shifts to couple more strongly with theta from the mPFC. This dynamic switch suggests that in the amygdala, as in the better-studied HPC, theta-gamma coupling provides a framework for input selection. In the HPC, theta-nested gamma organizes the firing of neural ensembles on different phases of the ongoing theta oscillation (Lisman and Buzsáki, 2008; Lisman and Jensen, 2013). Distinct fast and slow bands of theta-coupled gamma oscillations (Belluscio et al., 2012) differentially synchronize the CA1 region with input from the entorhinal cortex and CA3, respectively (Colgin et al., 2009). Switches between these two processing modes permit neurons in CA1 to represent prospective and retrospective spatial locations, depending upon the dominant input (Bieri et al., 2014; Yamamoto et al., 2014). Here we find that the fast gamma band within the BLA is preferentially coupled to mPFC theta input, and that this input is strongest during periods of safety. Periods of threat, by contrast, are associated with increased coupling to locally recorded theta. It is unclear
