Fig. 10: A proposed model for the coordination between the two functionally opposing BLA → dBNST circuits.

In this model, we propose that when the anxiolytic information is transmitted to the BLA, it triggers the activation of aBLA→adBNST PNs. Apart from eliciting anxiolytic behaviors by directly stimulating the adBNST neurons, aBLA→adBNST PN activation also enhance the activity of the inhibitory interneurons in the lpBLA. The enhanced activation of these interneurons not only dampens the activity of anxiogenic lpBLA→ovBNST PNs, but also relieves the inhibition imposed by the aBLA interneurons onto aBLA→adBNST PNs, thereby further augmenting the activity of the latter. On the other hand, when the anxiogenic information is passed onto BLA, it activates lpBLA→ovBNST PNs and elicits anxiogenic behaviors through engaging the inhibitory ovBNST→adBNST microcircuit. In addition, it also activates the interneurons in aBLA, which further suppress the activity of anxiolytic aBLA→adBNST PNs with subsequent removal of their indirect inhibition onto lpBLA→ovBNST PNs via disengaging the local interneurons.