Figure 2.

Cellular plasticity in parvocellular paraventricular nucleus neurons following chronic stress. Chronic stress causes a number of neuroplastic changes in parvocellular neurons consistent with increased excitability, including (1) increased number of (excitatory) glutamergic (VGluT2) terminal appositions, (2) enhanced excitatory synaptic inputs (increase in mEPSC frequency), (3) enhanced NR2A/NR2B ratio, predictive of increased NMDA receptor calcium permeability, and (4) increased number of (putative excitatory) norepinephrine/epinephrine terminal appositions. In addition, there is evidence for reduced inhibition of the PVN neurons, in terms of (1) reduced GABAergic synaptic inputs (decrease in mIPSC frequency), (2) decreased expression of synaptic and extrasynaptic GABA_A receptor subunits, (3) decreased cannabinoid type 1 receptor signaling, and (4) reduced GR expression/signaling, in some, but not all, studies.