OPRK1 and depressive disorder: In sum, our findings support for the hypothesis that depression is linked to disruption of homeostatic control of cortical micronetwork and unveil dynorphin/KOR signaling and CLAGlu-PLPV circuit as a signal and circuit-based mechanism by which chronic stress evokes depression through dysfunction of PL micronetwork via impairing excitatory inputs from the CLA to PL PV neurons.