EB-mediated NPY expression and release

Neuropeptide Y (NPY) is an endogenous modulator of neuronal activity by regulating GABA and glutamate release. Previously, we found that estradiol modulates NPY expression in the hippocampal dentate gyrus. Here we investigated which estrogen receptor type activation is required for the NPY expression. Further, we determined effects of estrogen receptor activation on NPY release. Finally, we determined the contribution of estrogen-mediated remodeling of the GABAergic and glutamatergic network in relation to changes in coupling with NPY in ovariectomized rats. We found that activation of either estrogen receptor type increases NPY expression as well as NPY release in the dentate gyrus. We also found that compared to OVX rats, estrogen replacement increases the likeness of synergistic/antagonistic coupling between the NPY and GABAergic synapse genes while the glutamatergic synapse genes are less likely coupled with NPY. The data together suggest that estrogen plays a critical role in regulation of activity of the NPY system and its coupling to GABAergic and glutamatergic synapses in female rat dentate gyrus. Two-conditions (E = beta-estradiol replacement vs O = oil) experiment. Biological replicates: 4E, 4O.