Specific activation of the GABAARN-to-GnRH neuron circuit with optogenetic and chemogenetic tools elicits LH secretion and mimics some features of PCOS, such as disrupted ovulatory cycles, reduced presence of corpora lutea in the ovary, and an increase in circulating testosterone [17], suggesting that modifications in this circuit may underpin the elevated LH secretion evident in PNA-treated, PCOS-like mice. Here, GNRH1 is linked to polycystic ovary syndrome.