Cholecystokinin-expressing interneurons mediated inhibitory transmission and plasticity in basolateral amygdala modulate stress-induced anxiety-like behaviors in mice.

The basolateral amygdala (BLA) hyperactivity has been implicated in the pathophysiology of anxiety disorders. We recently found that enhancing inhibitory transmission in BLA by chemo-genetic activation of local interneurons (INs) can reduce stress-induced anxiety-like behaviors in mice. Cholecystokinin interneurons (CCK-INs) are a major part of INs in BLA. It remains unknown whether CCK-INs modulated inhibition in BLA can mediate anxiety. In the present study, we found that BLA CCK-INs project extensively to most local excitatory neurons. Activating these CCK-INs using chemo-genetics and optogenetics can both effectively suppress electrical-induced neuronal activity within the BLA. Additionally, we observed that direct and sustained activation of CCK-INs within the BLA via chemo-genetics can mitigate stress-induced anxiety-like behaviors in mice and reduce stress-induced hyperactivity within the BLA itself. Furthermore, augmenting inhibitory plasticity within the BLA through a brief, 10-min high-frequency laser stimulation (HFLS) of CCK-INs also reduce stress-induced anxiety-like behaviors in mice. Collectively, these findings underscore the pivotal role of BLA CCK-IN-mediated inhibitory transmission and plasticity in modulating anxiety.