The male reproductive system relies on a negative feedback loop, meaning that as rises above a certain level, the hypothalamus and pituitary are triggered to stop producing gnrh, fsh, and lh.

level of testosterone

Explanation:

The level of testosterone produced is a determinant factor which influences the effect they have on the hypothalamus and the pituitary in regulating the release of GnRH, FSH, and LH in the male reproductive system.  

A high level of testosterone would lead to the production of the hormone called inhibin, which is released into the blood. The GnRH and FSH, which are responsible for the initiation of spermatogenesis and secretion of testosterone in the testes, are inhibited by inhibin. This causes the GnRH and FSH from being produced further by the hypothalamus and pituitary when the testosterone level rises beyond normal level.

When the testosterone level drops below the normal level, the release of inhibin stops, while the hypothalamus and the pituitary resume the release of GnRH, FSH, and LH to initiate spermatogenesis and the secretion of testosterone.

i'm pretty sure it's spores