arcuate nucleus of the hypothalamus
In the estradiol benzoate (EB) primed ovariectomized (OVX) rat, EB initially binds to ERa in the plasma membrane that complexes with and transactivates metabotropic glutamate receptor 1a to activate b-endorphin neurons in the arcuate nucleus of the hypothalamus (ARH) that project to the medial preoptic nucleus (MPN).