7 weeks of chronic daily afternoon ( 12 h after lights-on ) injections of 500 ng melatonin into the vicinity of the suprachiasmatic nuclei ( scn ) caused a 66 % reduction in female reproductive tract weight relative to saline-injected controls ( p less than 0.01 ) , with 83 % of these animals having an imperforate vagina , and no animals having mature follicles .
C0700038
female reproductive tract
C0266414
imperforate vagina