Fig. 5.

Model of how stress may affect the HPG axis through GnIH. (A) Previously, it was known that both GCs and GnIH inhibited the HPG axis independently. These interactions are shown in blue. (B) We propose that GCs released in response to stress act on GnIH via GR to increase the inhibitory actions of GnIH on GnRH secretion and/or pituitary sensitivity, resulting in decreased LH release. Our proposed pathway of GC–GnIH interaction is represented in red, joining the previously established independent effects of GCs and GnIH on reproduction. Arrows represent stimulation; Ts represent inhibition. CNS, central nervous system; PNS, peripheral nervous system.