Lemaître B, Dreux C
Experientia. 1979 Apr 15;35(4):556-7. doi: 10.1007/BF01922769.
The physiological increase in plasma gonadotropin (LH and FSH) levels in newborn rats is indisputably influenced by light. Permanent illumination accentuates this increase, whereas darkness decreases it in 16-day-old female rats. In male rats of the same age, only permanent illumination was tested with the same results.