Given fear-associated enhancements in amygdala theta power in response to conditioned stimuli (Figure 2A; Likhtik et al., 2014; Popa et al., 2010; Seidenbecher et al., 2003), we asked whether theta-gamma coupling in the BLA was also enhanced during fear. Indeed, we found a pronounced strengthening of theta-gamma coupling during CS+ presentations (Figure 2B) compared to pretone (30 seconds before tone presentation), for both slow and fast gamma oscillations as well as a small band between 15 and 20 Hz (p<.05/21, Bonferroni-corrected; Figure 2B). Phase-phase coupling was also significantly stronger during the CS+ than pretone (Figure S3C).
