Testicular Feminization Mutation
fm (testicular feminization mutant) mice are a useful model to study HPG and HPA interactions. Consistent with previous reports that found increased HPA activation in response to pharmacological AR inhibition [89,90], Tfm mice also display increased HPA activation [95,96], such as increased anxiety-associated behaviors and corticosterone levels [95]. Interestingly, the locus coeruleus, a brain region implicated in the stress response, contains more neurons and has a larger volume in a Tfm rat model compared to wild-type [97], indicating that the lack of HPG-associated AR activation results in an overactivation of the HPA system. Results from studies using either pharmacological or genetic inhibition of the AR have consistently shown that an AR-mediated mechanism underlies HPA and HPG interactions.