Figure 6.

Model depicting known and unknown differences in homeostatic feedback between control and PNA mice. Left, in 3-week-old mice, prenatal androgen exposure programs GnRH neurons, lowering activity; circulating steroids are low. Middle, in diestrous adults, ovarian androgens have a negative feedback effect on upstream components of the reproductive axis in controls (top), but in PNA mice (bottom) ovarian androgens feed forward to increase GnRH release. Ovarian feedback at the pituitary is negative. Right, removal of ovarian factors eliminates activational androgen drive to GnRH neurons and removes negative feedback from the pituitary, allowing LH to rise despite reduced GnRH neuron activity. Far right, addition of DHT is activating at the central level in both control and PNA mice but has no feedback action at the pituitary.