design: Young male Wistar/ChR rats were killed by transcardial perfusion with 4% formaldehyde. After 5 h postfixation in this fixative, brains were infiltrated overnight with sterile 20% sucrose solution in sterile PBS. GnRH neurons were immunostained using our novel ImmunoLCM method. GnRH neurons were isolated from the preoptic region by laser capture microdissection and subjected to RNA sequencing (Illumina).